Color masterbatch resin composition for packaging material for photographic photosensitive material and packaging material

ABSTRACT

A color masterbach resin composition for a packaging material for a photographic photosensitive material which does not adversely affect photographic properties of the photographic photosensitive material, comprising a light-shielding material in a concentration thrice as much as or more that of the packaging material for a photographic photosensitive material, and a thermoplastic resin of which 50 wt. % or more is the same type as a thermoplastic resin occupying 50 wt. % or more of the total thermoplastic resin composing the packaging material for a photographic photosensitive material, production thereof, a packaging material for a photographic photosensitive material formed of a color masterbatch resin composition, and production thereof. In the color masterbatch resin composition and the packaging material for a photographic photosensitive material of the invention, light-shielding material is dispersed uniformly by employing a special resin composition, and thereby, adverse affects upon photographic hpotosensitive materials are prevented, and favorable appearance can be ensured. Moreover, fog with time, abnormal sensitivity, abrasion, pressure marks, etc. can be prevented.

This is a Continuation of application Ser. No. 08/502,137 filed Jul. 13,1995, now abandoned.

BACKGROUND OF INVENTION

This invention relates to a color masterbatch resin composition for apackaging material for a photographic photosensitive material,production thereof, a packaging material for a photographicphotosensitive material formed of a color masterbatch resin composition,and production thereof.

As the a packaging material for a photographic photosensitive material,there are a resin composition composed of 30 to 95 wt. % of EEA resincontaining 7 wt. % or more of EA and 5 to 70 wt. % of carbon black (EP A0 277598), and a resin composition composed of 5 to 90 wt. % of amodified polyolefin resin, 5 to 70 wt. % of carbon black having an oilabsorption value of 50 ml/100 g or more and volatile components of 3.5%or less, and 0 to 10 wt. % of a fatty acid and/or a fatty acid metalsalt (U.S. Pat. No. 5,262,471).

However, the above-mentioned conventional color masterbatch resincompositions are inferior in dispersibility of color materials includingmost light-shielding materials, and great agglomerates (lumps) of colormaterial occasionally deposit on the surface of molded packagingmaterials for a photographic photosensitive material. The lumps causeadverse affects, such as fog with time, abnormal sensitivity, abrasion,pressure marks and fog by abrasion, upon photographic photosensitivematerials packaged, and uniform coloring is difficult due to theinferior dispersibility. The deposition of lumps of color materialdegrades appearance of the packaging material.

In a color masterbatch process, frequency of contacts between amasterbatch resin composition and a thermoplastic resin for dilution notcontaining a light-shielding material is not so many. Therefore, when acolor masterbatch resin composition is diluted at a high ratio, e. g. 7times or more, by using a low grade kneading molding machine, thedispersion of a light-shielding material becomes insufficient. As aresult, various troubles occur, such as uneven coloring of moldedarticles, jetting troubles around gates, generation of microgrits andweldlines to degrade appearance of packaging materials, delamination,decrease of physical strength or the like.

SUMMARY OF THE INVENTION

An object of the invention is to resolve the above problems and toprovide a color masterbatch resin composition for a packaging materialfor a photographic photosensitive material which is excellent indispersibility, capable of coloring uniformly, rare generation ofmicrogrits, rare occurrence of die lip fouling, no adverse affects uponphotographic properties, and beautiful appearance, and a method ofproducing the same.

Another object of the invention is to provide a packaging material for aphotographic photosensitive material formed of the color masterbatchresin composition and a method of producing the same.

The present invention provides a color masterbatch resin composition fora packaging material for a photographic photosensitive material and amethod of producing the same which have achieved the above object, andhave the following aspects.

In an aspect of the invention, a color masterbach resin composition fora packaging material for a photographic photosensitive material whichdoes not adversely affect photographic properties of the photographicphotosensitive material, comprising a light-shielding material in aconcentration thrice as much as or more that of the packaging materialfor a photographic photosensitive material, and a thermoplastic resin ofwhich 50 wt. % or more is the same type as a thermoplastic resinoccupying 50 wt. % or more of the total thermoplastic resin composingthe packaging material for a photographic photosensitive material.

In another aspect of the invention, a color masterbach resin compositionfor a packaging material for a photographic photosensitive materialwhich does not adversely affect photographic properties of thephotographic photosensitive material, comprising a light-shieldingmaterial in a concentration thrice as much as or more that of thepackaging-material for a photographic photosensitive material, and athermoplastic resin of which 50 wt. % or more is the same type as athermoplastic resin occupying less than 50 wt. % of the totalthermoplastic resin composing the packaging material for a photographicphotosensitive material.

In another aspect of the invention, a color masterbatch resincomposition for a packaging material for a photographic photosensitivematerial comprising 0.5 to 80 wt. % of a black light-shielding material,99.4 to 9.8 wt. % of a thermoplastic resin, and 0.01 to 10 wt. % intotal of one or more members selected from the group consisting ofpartially saponified fatty acid ester metal salts, fatty acids and fattyacid compounds.

In another aspect of the invention, a color masterbatch resincomposition for a packaging material for a photographic photosensitivematerial comprising 100 parts by weight of a resin compositionconsisting of 40 to 99.5 parts by weight of a polystyrene resin and/or apolyolefin resin and 0.5 to 60 parts by weight of carbon black, 0.01 to10 parts by weight of a metal salt of a partially saponified fatty acidester having 20 to 50 carbon atoms and/or a metal salt of a fatty acidhaving 15 to 50 carbon atoms, 0 to 1 part by weight of an antioxidantand 0 to 40 parts by weight of a low molecular weight polyolefin resin.

In another aspect of the invention, a color masterbatch resincomposition for a packaging material for a photographic photosensitivematerial comprising 10 to 500 parts by weight of a thermoplastic resininactive to polyolefin resin 100 parts by weight of a light-shieldingmaterial, and 10 to 500 parts by weight of an ester compound representedby the general formula ROOCR', wherein R is an alkyl group or acycloalkyl group having 11 to 28 carbon atoms of, and R' is an alkylgroup having 1 to 8 carbon atoms.

In another aspect of the invention, a color masterbatch resincomposition for a packaging material for a photographic photosensitivematerial comprising 3 to 40 wt. % of a polyolefin resin, 3 to 40 wt. %of a low crystallinity resin, 5 to 60 wt. % of a light-shieldingmaterial, and 0.01 to 10 wt. % of a lubricant.

In another aspect of the invention, a color masterbatch resincomposition for a packaging material for a photographic photosensitivematerial comprising 100 parts by weight of a polyolefin resin mixturecomprising of 40 to 98 wt. % of a polyolefin resin and 2 to 60 wt. % ofa modified polyolefin copolymer resin having a crystallinity of 1 to 40%produced by graft polymerization of a polyolefin resin with 0.05 to 2wt. % of maleic anhydride, 5 to 100 parts by weight of furnace carbonblack, and 0.001 to 5 parts by weight of a lubricant.

In another aspect of the invention, a color masterbatch resincomposition for a packaging material for a photographic photosensitivematerial comprising 100 parts by weight of a polyolefin resin mixturecomprising of 40 to 98 wt. % of a polystyrene resin having a rubbercontent of 15 wt. % or less and 2 to 60 wt. % of a modified polyolefincopolymer resin having a crystallinity of 1 to 40% produced by graftpolymerization of a polyolefin resin with 0.05 to 2 wt. % of maleicanhydride, 5 to 100 parts by weight of furnace carbon black, and 0.001to 5 parts by weight of a lubricant.

In another aspect of the invention, a method of producing a colormasterbatch resin composition comprising diluting with a resin, a highconcentration masterbatch resin composition comprising 1 to 80 wt. % ofa light-shielding material prepared in the presence of 0.001 to 5 wt. %of an antioxidant and 0.01 to 10 wt. % of a fatty acid metal salt.

The present invention also provides a packaging material for aphotographic photosensitive material formed of a color masterbatch resincomposition and a method of producing the same which have achieved theabove object, and have the following aspects.

In an aspect of the invention, a packaging material for a photographicphotosensitive material comprising a color masterbatch resin compositionof a packaging material which comprises a thermoplastic resin and alight-shielding material fo which surface has been coated with asurface-coating material dispersed into the thermoplastic resin, a resincomposition for dilution, and at least a lubricant or an antistaticagent.

In an aspect of the invention, a packaging material for a photographicphotosensitive material comprising a color masterbatch resin compositionfor a packaging material comprises 100 parts by weight of a polystyreneresin and/or an ABS resin, 0.2 to 50 parts by weight of carbon black and0.02 to 10 parts by weight of a lubricant, and a thermoplastic resin fordilution.

In an aspect of the invention, a method of producing a packagingmaterial for a photographic photosensitive material which comprises,mixing a color masterbatch resin composition with a thermoplastic resinfor dilution in an amount twice as much as or more of the colormasterbatch resin composition, keeping a hopper and a resin feed openingof an extruder under reduced pressure conditions lower than anatmospheric pressure.

In an aspect of the invention, a method of producing a packagingmaterial for a photographic photosensitive material which comprisesmixing 100 parts by weight of a color masterbatch resin composition fora packaging material with 300 parts by weight or more of a thermoplasticresin for dilution by a mixer almost uniformly, providing a line mixerwithout any movable part between an extruder and a mold, and supplyingthe mixed resin in a melted state to the mold through the line mixer.

In an aspect of the invention, a method of producing a packagingmaterial for a photographic photosensitive material which comprisesmixing pellets of a color masterbatch resin composition for a packagingmaterial for a photographic photosensitive material with pellets of athermoplastic resin for dilution in a predetermined ratio by anautomatic weighing mixer, removing evaporable substances from the resinmixture through their evaporation by keeping a hopper and a resin feedopening of an extruder to which the mixed pellets are supplied underreduced pressure conditions lower than an atmospheric pressure, and thenmolding the resin mixture.

In an aspect of the invention, a method of producing a packagingmaterial for a photographic photosensitive material which comprisesmixing pellets of a color masterbatch resin composition for a packagingmaterial for a photographic photosensitive material with pellets of arubber-containing polystyrene resin for dilution in a predeterminedratio by a mixer almost uniformly, injecting the resin mixture into amold of which a wall temperature of core and cavity portions is from110° to 250° C., and taking the molded packaging material out of themold when the wall temperature of core and cavity is less than a glasstransition temperature of the rubber-containing polystyrene resin.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1 through 9 are partial sectional views of packaging materials fora photographic photosensitive material embodying the invention,respectively.

FIGS. 10 and 11 are sectional views of cap separated from body-typecontainers for a photographic film embodying the invention.

FIG. 12 is a perspective view of a cap-body integrated type containerfor a photographic film embodying the invention.

FIG. 13 is a front view of a photographic film spool embodying theinvention.

FIG. 14 is an exploded perspective view of a photographic film cartridgeembodying the invention.

FIG. 15 is a perspective view of a photographic film cartridge made ofresin embodying the invention.

FIG. 16 is an exploded perspective view of a photographic film unit witha lens embodying the invention.

FIG. 17 is a sectional view of a cap-body integrated type photographicfilm case embodying the invention.

FIG. 18 is an exploded perspective view of a photographic film cartridgeembodying the invention.

FIG. 19 is a perspective view illustrating a packaging process of apackage of a photographic photosensitive strip material using alight-shielding film having a light-shielding thermoplastic resin filmlayer embodying the invention.

FIG. 20 is a schematic illustration of a line mixer without any movablepart.

1a . . . Light-shielding thermoplastic resin film layer (packagingmaterial for photographic photosensitive material)

2, 2a . . . Thermoplastic resin layer

3 . . . Intermediate layer

4 . . . Adhesive layer

5 . . . Flexible sheet layer

9 . . . Metallized biaxially stretched film layer

10 . . . Metal foil

a . . . indicating to contain a light-shielding material

DETAILED DESCRIPTION OF THE INVENTION

As the resin component of the color masterbatch resin composition of theinvention, polyolefin resins and polystyrene resins are preferred.

The polyolefin resins are crystalline olefin polymers of which theessential monomer is an olefin, and illustrative of the polyolefinresins are low density hompolyethyelene resins, medium densityhomopolyethylene resins, high density homopolyethylene resins, ethylenecopolymer resins, homopolypropylene resins, propylene-α-olefin copolymerresins (illustrative of α-olefins are ethylene, butene-1, hexene-1,4-methylpentene-1, octene-1, etc.), polybutene resins, polymethylbuteneresins, polymethylpentene resins, etc.

Representative ethylene copolymer resins are ethylene-vinyl acetatecopolymer (EVA) resin, ethylene-propylene copolymer resin,ethylene-1-butene copolymer resin, ethylene-butadiene copolymer resin,ethylene-vinyl chloride copolymer resin, ethylene-methylmethacrylatecopolymer (EMM) resin, ethylene-methyl acrylate copolymer (EMA) resin,ethylene-ethyl acrylate copolymer (EEA) resin, ethylene-acrylonitrilecopolymer resin, ethylene-acrylic acid copolymer (EAA) resin, ionomerresin (copolymer of ethylene and unsaturated acid crosslinked usingmetal such as zinc), ethylene-α-olefin copolymer (L-LDPE) resin,ethylene-propylene-butene-1 ternary copolymer resin, polyethylene resinelastomer, and the like.

The L-LDPE resin is called third polyethylene resin, and it is a lowcost high strength resin, having the advantages of both low, mediumdensity polyethylene resin and high density polyethylene resin, whichmeets the requirements, i.e. resource conservation and energyconservation, of the time. The L-LDPE resin is a copolymer of ethyleneand α-olefin, and it has a linear structure having short branches. Thenumber of carbon atoms of the α-olefin is 3 to 13. Preferable α-olefinhas a number of carbon atoms of 4 to 10, and examples of the α-olefinare butene-1, pentene-1, 4-methylpentene-1, 3-methylpentene-1, hexene-1,4,4-dimethylpentene-1, heptene-1, octene-1, nonene-1, decene-1,undecene-1, dodecene-1, etc. The density (ASTM D-1505) is usually in thedegree of low, medium polyethylene resin and most of commercial resinsare in the range of 0.87 to 0.97 g/cm³. Melt flow rate (ASTM D-1238,Condition E) is mostly in the range of 0.1 to 80 g/10 minutes.

As the polymerization process of L-LDPE resin, there are the vaporprocess and the liquid slurry process using a medium, low pressureapparatus and the ion polymerization process using an apparatus for thehigh pressure modified method.

Examples of commercial L-LDPE resin are "G-Resin" and "TUFLIN" (UCC),"NUC Polyethylene-LL" and Moretec (Idemitsu Petrochemical), "Dowlex"(Dow chemical), "Suclear" (Dupont de Nemour, Canada), "Marlex"(Phillips), "Neozex" and "Ultzex" (Mitsui Petrochemical Industries),"Nisseki Linirex" (Nippon Petrochemicals), "Stamilex" (DSM) "MitsubishiPolyethy-LL" (Mitsubishi Petrochemical), and the like. Very low densityL-LDPE resins having a density of less than 0.910 g/cm³ are alsopreferred, such as "NUC-FLX" (UCC) and "Excelene VL" (SumitomoChemical).

Preferable L-LDPE resins for film molded articles in view of physicalstrength, heat seal strength and inflation film moldability arecopolymers of ethylene and α-olefin, of which the number of carbon atomsis 6 to 8, having a melt flow rate (MFR) of 0.8 to 10 g/10 minutes,preferably 1 to 7 g/10 minutes (ASTM D-1238, Condition E) and a densityof 0.870 to 0.940 g/cm³, preferably 0.890 to 0.930 g/cm³ (ASTM D-1505)manufactured by the liquid slurry process or the vapor process.Preferable L-LDPE resins for injection molded articles in view of thebalance between physical strength and, injection moldability arecopolymers of ethylene and α-olefin, of which the number of carbon atomsis 3 to 8, having a melt flow rate (MFR) of 2 to 80 g/10 minutes,preferably 5 to 50 g/10 minutes (ASTM D-1238, Condition E) and a densityof 0.890 to 0.985 g/cm³, preferably 0.900 to 0.980 g/cm³ (ASTM D-1505)manufactured by the liquid slurry process or the vapor process.

Representative polystyrene resins include styrene resins, ABS resins,acrylonitrile-styrene resins, AAS (ASA) resin and AES resins.

I. Styrene Resin

There are clear general purpose polystyrene (GPPS) resins which arehomopolystyrene resin produced by polymerizing styrene monomer alone andhigh impact polystyrene (HIPS) resin which are rubber-containingpolystyrene resin, i.e. homopolystyrene resin reinforced by a rubbermaterial. Polystyrene portions of both resins are linear and amorphous.When using a Natta catalyst, isotactic polystyrene is obtained. It isopaque and thermal deformation temperature is about 200° C.Characteristics of styrene resin are specific gravity being greater thanpolyolefin resin but smaller than metal, tasteless, odorless, non-toxic,small hygroscopicity, excellent electrically insulating ability andradiofrequency inslating ability, good coloring and coating ability,very excellent moldability, good dimensional stability of moldedarticles, relatively cheap material, etc. On the other hand,disadvantages according to use are insufficient impact strength,corrosion by a part of oils and of organic solvents, insufficient heatresistance, easy combustion, insufficient weatherability, easyelectrification.

Polystyrene resins are produced mostly by continuous bulk polymerizationand partly by batch suspension polymerization, both are typical radicalpolymerization. The continuous bulk polymerization is an ideal processwherein a polymerization process, a degassing and monomer recoveringprocess and a granulating process are combined continuously, andremarkable improvement is considered difficult.

As the rubber-containing aromatic monovinyl resin which includesrubber-containing polystyrene resin (also called high-impact polystyreneresin), there are embodiments of polymers of a rubber material and anaromatic monovinyl monomer, mixtures formed by mere blending a rubbermaterial with an aromatic monovinyl resin, and mixtures of a polymer ofa rubber material and aromatic monovinyl monomer and an aromaticmonovinyl resin.

A suitable rubber material content of the rubber-containing aromaticmonovinyl resin is 1 to 12 wt. %, preferably 1.5 to 10 wt. %,particularly preferably 2 to 8 wt. %, in view of the balance betweenphysical strength required as the packaging material for a photographicphotosensitive material of the invention and adverse affects uponphotographic properties. The content of less than 1 wt. % results ininsufficient physical strength and wear resistance, particularly ininsufficient dropping strength for photographic film spools,photographic film cartridges, instant film units, camera bodies,photographic film magazines and photographic film units with a lenswhich are frequently used under low temperature conditions of lower than0° C. On the other hand, the content of more than 12 wt. % results inthe increase of fogging by 0.03 or more and in the partial increase ofsensitivity by 20% or more to generate uneven density in a print, withtime during storing a photographic photosensitive material for 3 monthsor more in sealed conditions. Moreover, bending elastic modulus isdecreased.

The rubber material is ethylene-propylene copolymer,ethylene-propylene-nonconjugative diene ternary copolymer, isoprenecopolymer, polyisobutylene, styrene-isoprene copolymer, polybutadiene,styrene-butadiene copolymer and the like. The polybutadiene may be ahigh cis-polybutadiene preferably having a cis 1,4-bond content of 70mol. % or more, particularly preferably 90 mol. % or more, or a lowcis-polybudddiene having a low cis content.

A suitable mean particle size of the rubber material is 0.1 to 10 μm,preferably 0.2 to 7 μm, more preferably 0.5 to 5 μm, the most preferably0.7 to 3.5 μm. The mean particle size of less than 0.1 μm results in thedecrease of impact strength, and abrasion troubles frequently occur. Themean particle size of more than 10 μm results in a great surfaceroughness, and tensile strength decreases. In general, when the meanparticle size is small, molded articles have a high gloss and surfacesmoothness. However, the surface tends to be damaged, and thepolymerization cost increases. On the other hand, when the mean particlesize is great, reflection decreases to lower gloss. Accordingly, in thecase of obtaining a high gloss molded article, resin blended with arubber material having a mean particle size of 0.1 to 1.5 μm, preferably0.2 to 1 μm, is used. In the case of obtaining a mat molded article witha low gloss in order to prevent reflection, resin blended with a rubbermaterial having a mean particle size of 1.5 to 10 μm, preferably 1.7 to7 μm, particularly preferably 2 to 5 μm, is used. By using the rubbermaterial having the greater particle size, fogging caused by lightreflection can be avoided unless embossing is provided on the surface.However, to provide embossing is preferred because fogging caused bylight reflection can be prevented more completely.

The mean particle size of the rubber material is determined by slicingthe rubber material particle into very thin laminas by a microtome,photographing by a transmission electron microscope, and measuring eachparticle size of 600 particles of the rubber material in photographs.The mean particle size is calculated by the following formula.

    Mean Particle Size=ΣnD.sup.2 /ΣnD

In the formula, n is particle size, and D is the number of particles ofthe rubber material.

The mean particle size of the rubber material can be controlled byadjusting stirring conditions upon polymerization, viscosity of rubbermaterial solution, or the like.

The aromatic monovinyl monomer includes styrene, alkylated styrenes atthe nucleus, such as o-methylstyrene, p-methylstyrene, m-methylstyrene,2,4-dimethylstyrene, ethylstyrene and p-tert-butylstyrene, halogenatedstyrenes at the nucleus, such as 2,4,6-tribromostyrene and2,4,6-trichlorostyrene, α-alkyl substituted styrenes, such asα-methylstyrene and α-methyl-p-methylstyrene, and the like. In addition,methacrylate esters, acrylate esters, acrylonitrile and maleicanbydride, which are copolymerizable with a styrene monomer, areincluded.

Among the rubber-containing aromatic monovinyl resins, the polymer of arubber material and an aromatic monovinyl monomer can be produced by thefollowing polymerization methods,

(A) Radical Polymerization

1 Batch Bulk Polymerization

Advantages . . . Produced in a simple process.

Disadvantages . . . Difficulty in heat diffusion in a large scaleproduction. Molecular weight distribution is broad, and moldability isinferior.

2 Continuous Bulk Polymerization

Advantages . . . Quality of the product is uniform. Manufacturing costis cheap.

Disadvantages . . . Transportation of a high viscosity reactionsolution, and channeling phenomenon in a reaction tower.

3 Continuous Solution Polymerization

Advantages . . . Control of polymerization heat is easy.

Disadvantages . . . Removal of solvent is necessary. Stirring isdifficult.

4 Suspension Polymerization

Advantages . . . Removal of polymerization heat is possible. Granularpolymer can be obtained. Residual amount of monomer is small.

Disadvantages . . . Contamination by water and stabilizer occurs.Removal of volatile components is necessary. Drying and pelletizing arenecessary.

5 Emulsion Polymerization

Advantages . . . Reaction rate is great. Removal of polymerization heatis possible. Continuous polymerization is possible. Polymer in latex canbe obtained.

Disadvantages . . . Contamination by water and emulsifier occurs. Dryingand pelletizing are necessary.

(B) Ion Polymerization

1 Ion Polymerization

Advantages . . . Reaction rate is great. Control of polymerization heatis possible.

Disadvantages . . . Removal of solvent and catalyst powder arenecessary. Refrigeration is necessary.

Among the above polymerization methods, the bulk polymerization andbulk-suspension two-step polymerization wherein styrene monomer ispolymerized through radical reaction in the presence of rubber polymerare preferable in economical viewpoint, and the continuous bulkpolymerization is particularly preferred. On the other hand, thesuspension polymerization (in a batch form) is also preferable in viewof a small amount of residual monomer, the excellence in heat resistanceand the capability of a sharp turn.

A suitable melt flow index (MFI, ASTM D-1238, Condition G) of therubber-containing aromatic monovinyl resin is 3 to 40 g/10 minutes,preferably 5 to 35 g/10 minutes, more preferably 7 to 30 g/10 minutes,the most preferably 10 to 25 g/10 minutes. The MFI of less than 3 g/10minutes results in the frequent occurrence of short shot and weld linesdue to the inferiority of resin fluidity and in the lengthening ofmolding cycle. On the other hand, the MFI of more than 40 g/10 minutesresults in small physical strength, the frequent occurrence of burrs andthe tendency to thermal degradation.

A suitable number average molecular weight of the rubber-containingaromatic monovinyl resin is 10,000 to 1,000,000, preferably 20,000 to800,000, particularly preferably 50,000 to 600,000, in view of thebalance between physical strength and polymerization cost and injectionmoldability.

A suitable bending elastic modulus (ASTM D-790) of the rubber-containingaromatic monovinyl resin is 20,000 kg/cm² or more, preferably 22,000kg/cm² or more, more preferably 23,000 kg/cm² or more, the mostpreferably 25,000 kg/cm² or more. When the bending elastic modulus isless than 20,000 kg/cm², dimensional stability and completelight-shielding ability cannot be ensured due to the tendency todeformation by external force. Particularly, in the case of photographicfilm spools and photographic film cartridges made of resin (includingK16 film and K35 film) used by loading into a camera, the deformationresults in the difficulty in the loading into a camera, andphotographing becomes impossible.

A suitable Vicat softening point (ASTM D-1525) of the rubber-containingaromatic monovinyl resin is 78° C. or more, preferably 82° C. or more,more preferably 85° C. or more, the most preferably 87° C. or more. Whenthe Vicat softening point is less than 78° C. in the case of the moldedarticles colored black, they are softened to deform by leaving in anauto car under the sunlight for 1 hour or more, and as a result,complete light-shielding cannot be ensured.

In the case of spools, they cannot be rotated smoothly by the occurrenceof deformation.

A suitable Rockwell hardness (ASTM D-785) of the rubber-containingaromatic monovinyl resin is M40 or more, preferably M45 or more, morepreferably M50 or more, the most preferably M55 or more. The Rockwellhardness of less than M40 results in the occurrence of abrasion causedby the friction with a cartridge made of metal, a cap, photographic filmor the like, in the increase of winding torque, in the difficulty toensure dimensional stability, and in the occurrence of spots by theadhesion of abrasion dust on a photographic photosensitive material.

A suitable Izod impact strength (ASTM D-256) of the rubber-containingaromatic monovinyl resin is 2.0 k·cm/cm or more, preferably 2.5 kg·m/cmor more, more preferably 3.0 kg·m/cm or more, the most preferably 3.5kg·m/cm or more. When the Izod impact strength is less than 2.0 kg·m/cm,physical strength is small. Particularly, in the case of photographicfilm spools, photographic film cartridges made of resin, instant filmunits, camera bodies and photographic film units with a lens which arefrequently used under low temperature conditions of lower than 0° C.their dropping strength is insufficient, and to ensure completelight-shielding ability is difficult by cracking or breakage.

II. ABS Resin

ABS resin is a thermoplastic resin of which the principal components areacrylonitrile (A), butadiene (B) and styrene (S). AS copolymer isgrafted from polybutadiene partices, and accordingly, compatibilitybetween polybutadiene particles and AS continuous phase is excellent,and aggregation of polybutadiene particles cannot be observed. Since ABSresin is in a grafted rubber particle dispersion system similar to highimpact polysyrene (HIPS) resin, viscoelasticity temperaturecharacteristics are divided into the dispersion absorption around -80 ypolybutadiene rubber and the dispersion absorption around +120 y AScopolymer. Impact strength which is the most characteristic of ABS resinmay depend on the absorption of impact energy by deforming polybutadieneparticles and on the absorption of impact energy by crazes generated atthe interface between polybutadiene particles. The mechanism ofinhibiting transmission and destroy of crazes as well as the generationof crazes may also be important in order to further raise impactstrength. ABS resin is excellent in moldability, such as in injectionmolding, extrusion molding and vacuum molding, and also excellent inrigidity and chemical resistance. Coloring by a light-shielding materialis excellent, and secondary processings, such as coating, printing, hotstamping, vacuum deposition and plating are also excellent. Blends withother resins, such as polycarbonate resin and polyvinyl chloride resinform characteristic commercial goods as ABS alloys. Only defect isinferior weatherability, and improvement therefor is investigated as toadditives such as an age-resistor and resin composition.

ABS resin is produced by graft blending, bulk uspension polymerizationor emulsion·continuous bulk polymerization. In the graft blending, anABS resin having a high rubber content is prepared by reactingpolybutadiene latex with acrylonitrile/styrene monomer, followed byblending an AS copolymer resin separately prepared to obtaine aprescribed ABS resin. In the bulk uspension polymerization,uncrosslinked rubber is dissolved in styrene monomer, and preliminarybulk polymerization is carried out in a rubber matrix state. When phasetransition to a rubber suspension state, grafting in a suspension systemis carried out to obatain the ABS resin. Since it is difficult toproduce a ABS resin having a high rubber content according to thismethod, a way of producing the object ABS resin is to blend with an ABSresin produced by another method or AS copolymer resin. In the emulsionontinuous bulk polymerization, an ABS latex having a high rubber contentprepared by emulsion polymerization is mixed with Acrylonitrile/styrenemonomer and an electrolite, and water separated is removed to obtain anABS crumb. acrylonitrile/styrene monomer is added to the ABS crumb tomake an ABS dope, and continuous bulk polymerization is carried out toobtain the ABS resin. In this method, since coagulation, washing withwater and drying of ABS resin powder are not necessary, a great decreasein cost is possible.

III. Acrylonitrile-Styrene Resin

Since styrene is a representative vinyl monomer, copolymers with variousmonomers have been developed. Among the copolymers of styrene and othercomonomers, commercialized transparent highly rigid (not reinforced byrubber) resins are acrylonitrile-styrene (AS) resin,methylmethacrylate-styrene (MS) resin and maleic anhydride-styreneresin. These styrene resins are produced, in general, by radicalpolymerization, and their molecular structures are of typical randomcopolymer resin, and are different from rubber-graft modified copolymerresin, such as high impact polystyrene resin which is arubber-containing polystyrene resin. In the transparent copolymerresins, when the resin composition is shipped only by several percents,the transparency sharply degrades. Accordingly, how to maintain thecomposition destribution is an important point in the production. Forexample, in the case of AS resin, since azeotropic composition is ofstyrene monomer/acrylonitrile=75/25, commercial AS resins have mostly anAN content of 25 to 35% and a composition distribution of ±1%. Since theinner rotation of molecular chain is inhibited by the introduction ofpolar groups and bulky side chains by the copolymerization, theacrylonitrile-styrene resins are superior in mechanical properties, heatresistance, chemical resistance, etc. compared with general purposehomopolystyrene resin.

The acrylonitrile-styrene resin is produced by bulk polymerization orsuspension polymerization due to the restriction by quality requirementand economical viewpoint. For example, AS resin is naturally possible tobe produced similar to GPPS resin, but various problems accompanied bythe introduction of acrylonitrile comonomer (such as, increase ofpolymerization reaction heat, increase of viscosity of polymerizationsystem, composition distribution, etc.) are important. Generallyspeaking, bulk polymerization is disadvantageous in equipment cost, butadvantageous is stable quality due to no contamination with impuritiesand economical advantage due to continuous polymerization.

IV. AAS (ASA) Resin and AES Resin

The fundamental structure of the AAS (ASA) resin is ##STR1## (AScopolymer). However, in the acrylic rubber, other acrylic acid esterssuch as ethyl acrylate is used as monomer unit in addition to n-butylacrylate. The monomer unit ratio of styrene and acrylonitrile in the AScopolymer varies according to grades.

The fundamental structure of AES resin is composed of ##STR2## However,the monomer unit ratio of styrene and acrylonitrile in the AS copolymervaries according to grades.

The AAS (ASA) resin and AES resin are characterized by the superiorityin weatherability and impact resistance, and moldability and appearanceof molded articles are excellent. The excellent impact resistance is dueto the dispersion of acrylic rubber particles or EPDM rubber particleswhich absorbs impact energy. The excellent weatherability is due to theremarkable stability of acrylic rubber and EPDM rubber against UVdegradation compared with butadiene rubber in ABS resin, etc.

The AAS (ASA) resin is produced by adding several percents of acrosslinking agent or a grafting agent to n-butyl acrylate, and emulsionpolymerization is carried out to form a rubber latex. Then, styrene andacrylonitrile are added to the rubber latex, and graft copolymerizationis carried out. After the polymerization, subjected to salting out toobtaine resin powder. The AES resin is produced by dissolving EPDMrubber in an organic solvent, and graft copolymerization is carried outby adding styrene and acrylonirile. There is a method wherein theorganic solvent is not used. After polymerization, the solvent isremoved the obtain resin powder.

Taking into consideration the case of reclamation treatment as waste,degradable platic which is being developed or has already introduced inthe market can be used. For example, a biodegradable polymer of "BIOPOL"(ICI), "Polycaprolactone" (UCC) or the like is utilized, or a polymerindirectly collapsed by blending a biodegradable natural or syntheticpolymer as an additive, such as polyethylene blended with starch, can beutilized. In order to improve industrial waste treatment, it is alsopreferable to blend a recently commercialized synthetic biodegradableplastic which can be decomposed up to carbon dioxide and water by theaction of microoragnisms ("Bionol", Showa Polymer, which is a specialpolyester resin synthesized from dicarboxylic acid and the like, apolymer alloy of modified polyvinyl alcohol having biodegradability andmaize starch) in an amount of not less than 10 wt. % of the resincomposition for the molded article. In the case of a multilayer moldedarticle, it is preferable so that the layer(s) which do not contactdirectly photographic photosensitive materials contain not less than 50wt. % of the above biodegradable plastic in view of the improvement inindustrial waste treatment.

Moreover, it is also possible to utilize a photodegradable polymer, suchas ELCO copolymer wherein carbonyl groups are introduced into the mainchain as a photosensitization group at the time of polymerization ofethylene, i.e. copolymerization of ethylene and carbon monoxide,polymers to which photodegradability is imparted by adding transitionmetal salt, oxidation accelerator, photosensitizer or the like to basepolymer. It is also possible to combine degradable polymers, such asbiodegradable polymer, photodegradable polymer and water-soluble polymer(Japanese Patent KOKAI No. 3-129341). When recycling is taken intoconsideration, it is preferable to form all of the packaging materialfor a photographic photosensitive material by the same or similar resincomposition. For example, it is preferable that all of a cartridge body,a spool and a babel with print constituting a cartridge for aphotographic film is made of a polystyrene resin or polypropylelenresin, and all of a spool, an upper case and a lower case of a film unitwith a lens is made of a polystyrene resin or polypropylelen resinhaving complete light-shielding ability.

Low crystallinity thermoplastic resins can also be used. The lowcrystallinity thermoplastic resin is a general term of rubber-containingthermoplastic resins and modified polyolefin resins, and includesthermoplastic resin elastomers, ethylene-vinyl acetate copolymer resins(having a vinyl acetate content of 5 to 40 wt. % are preferred.),ethylene-ethyl acrylate copolymer resins (having an ethyl acrylatecontent of 5 to 30 wt. % are preferred.), ethylene-α-olefin copolymerresins (having an α-olefin content of 5 to 40 wt. % are preferred.),thermoplastic butadiene resins (preferred are syndiotactic1,2-polybutadiene containing 90% or more of 1,2-bonds.), chlorinatedpolyethylene resin (chlorine content: 20 to 50 wt. %), and the like. Theα-olefin has a number of carbon atoms of 3 to 15, preferably 3 to 8 suchas propylene, butene-1, 4-methylpentene-1, hexene-1, heptene-1 andoctene-1.

The acid-modified polyolefin resin is a modified resin of polyolefinresin graft-modified with unsaturated carboxylic acid compound, andincludes graft-modified polyethylene resin, graft-modified polypropyleneresin, and graft-modified ethylene copolymer resins, such asgraft-modified ethylene-ethyl acrylate copolymer resin, graft-modifiedethylene-vinyl acetate copolymer resin, graft-modified L-LDPE resin andgraft-modified ethylene-methyl acrylate copolymer resin, and the like.

The unsaturated carboxylic acid compound usable as the modifier of thepolyolefin resin is acrylic acid, methacrylic acid, crotonic acid,isocrotonic acid, fumaric acid, maleic acid, itaconic acid, citraconicacid, angelic acid, tetrahydrophthalic acid, sorbic acid, mesaconicacid, nudic acid (end-cis-bicyclo 2,2,1!-hepto-5-en-2,3-dicarboxylicacid), maleic anhydride, itaconic anhydride, citraconic anhydride,methyl acrylate, methyl methacrylate, ethyl methacrylate, ethylacrylate, n-butyl acrylate, glycidyl acrylate, glycidyl methacrylate,glycidyl maleate n-butyl methacrylate, maleic acid monoethyl ester,maleic acid diethyl ester, fumaric acid monoethyl ester, fumaric aciddimethyl ester, itaconic acid diethyl ester, acrylamide, methacrylamide,maleic acid monoamide, maleic acid diamide, maleicacid-N-monoethylamide, maleic acid-N,N-diethylamide, maleicacid-N-monobutylamide, maleic acid-N,N-dibutylamide, fumaric acidmonoamide, fumaric acid diamide, fumaric acid-N-monoethylamide, fumaricacid-N,N-diethylamide, fumaric acid-N-monobutylamide, fumaricacid-N,N-dibutylamide maleimide, N-butylmaleimide, N-phenylmaleimide,malonyl chloride, monomethylmaleate, dimethylmaleate, dipropylmaleate,potassium acrylate, sodium acrylate, zinc acrylate, magnesium acrylate,calcium acrylate, sodium methacrylate, potassium methacrylate, or thelike. Two or more unsaturated carboxylic acid compounds may be combined.Preferable unsaturated carboxylic acid compounds are acrylic acid,maleic acid, maleic anhydride and nudic acid, and maleic anhydride isparticularly preferred. A suitable amount of the unsaturated carboxylicacid compounds is 0.01 to 20 parts by weight, preferably 0.2 to 5 partsby weight, per 100 parts by weight of the polyolefin base resin in viewof securing adhesive strength.

The grafting modification method may be any known method, such as themethod of reacting in a melted state disclosed in Japanese Patent KOKOKUNo. 43-27421, the method of reacting in a solution state disclosed inJapanese Patent KOKOKU No. 44-15422, the method of reacting in a slurrystate disclosed in Japanese Patent KOKOKU No. 43-18144 and the method ofreacting in a vapor state disclosed in Japanese Patent KOKOKU No.50-77493. Among them, the melting method using an extruder is preferredbecause of simple operation and inexpensiveness.

A peroxide is added in order to accelerate the reaction between thepolyolefin base resin and the unsaturated carboyxlic acid. Suitableperoxides are organic peroxides such as benzoyl peroxide, lauroylperoxide, dicumyl peroxide, α, α'-bis(t-butylperoxydiisopropyl)benzene,2,5-dimethyl-2,5-di(t-butylperoxy)hexane,2,5-dimethyl-2,5-di(t-butylperoxy)hexyne, di-t-butyl peroxide, cumenehydroperoxide, t-butyl-hydroperoxide, t-butylperoxylaurate,t-butylperoxybenzoate, 1,3-bis(t-butylperoxyisopropyl) benzene,di-t-butyl-diperoxyphthalate, t-butylperoxymaleic acid and isopropylpercarbonate, azo compounds such as azobisisobutyronitrile, andinorganic peroxides such as ammonium persulfate. Two or more peroxidesmay be combined. Particularly preferred peroxides aredi-t-butylperoxide, dicumylperoxide,2,5-dimethyl-2,5-di(t-butylperoxy)hexane,2,5-dimethyl-2,5-di(t-butylperoxy)hexyne,1,3-bis(t-butylperoxyisopropyl)benzene and the like, which have adecomposition temperature between 170° C. and 200° C. A suitable amountof the peroxide is 0.005 to 5 parts by weight, preferably 0.01 to 1 partby weight per 100 parts by weight of the polyolefin base resin.

There are commercial adhesive polyolefin resins, such as "N polymer"(Nippon Petrochemicals), "Admer" (Mitsui Petrochemical Industries), "ERResin" (Showa Denko), "Novatec-AP" (Mitsubishi Chemical Industries),"Modic" (Mitsubishi Petrochemical), "NUC-Ace" (Nippon Unicar), "UbeBond" (Ube Ind.), "Bondain" (Sumitomo Chemical),"Melcene M" (Toso),"CMPS" (Mitsui Polychemicals), etc.

Furthermore, thermoplastic resins inactive to polyolefin resin can alsobe used for the color masterbatch resin composition of the invention.When the thermoplastic resin inactive to polyolefin resin is selectedfrom the compatibilizing agents described later, various excellenteffects can be exhibited, such as the improvement in physical strength,the improvement in appearance and the like as well as the improvement inhe dispersion of light-shielding material.

The thermoplastic resin inactive to polyolefin resin is not decomposedand does not accelerate the decomposition of polyolefin resin uponkneading with the polyolefin resin and molding with heating (extrusion,injection molding, etc.), and is not denatured nor degraded and does notinduce denaturation and degradation even if coexisting for a longperiod. The thermoplastic resin inactive to polyolefin resin hasthermoplasticity and blendability with polyolefin resin, and functionsas a dispersing medium for keeping the dispersion of light-shieldingmaterial. Illustrative of the thermoplastic resins inactive topolyolefin resin are homopolyethylene resins with a variety of density,L-LDPE resins, homopolypropylene resins, propylene-α-olefin copolymerresins, EVA resins, EEA resins, EMA resin, EAA resins, ionomer resins,EMMA resins, modified polyolefin resins, various thermoplasticelastomers (ethylene based, olefin based, vinyl chloride based, esterbased, amide based, etc., such as ethylene-propylene elastomer,polyisobutylene, etc.), in addition to the foregoing compatibilizingagents. Preferred ones are homopolyethylenes with a variety of density,L-LDPE resins, EEA resins, EVA resins, homopolypropylene resins,propylene-ethylene copolymer resins, various polyolefin based elastomersand compatibilizing agents.

An ester compound having the following general formula can be used forthe color masterbatch resin composition of the invention.

ROOCR'

Provided that, in the formula, R is an alkyl group or a cycloalkyl grouphaving a number of carbon atoms of 11 to 28, and R' is an alkayl grouphaving a number of carbon atoms of 1 to 8.

The ester compound is quite different from the lower alcohol esters ofhigher fatty acid wellknown as lubricant or spreading agents.

The ester compounds of which the number of carbon atoms of R is 10 orless have a high volatility, and the improvement in compatible affinityof medium polymer is small. Examples of such an ester compound are octylacetate and octyl propionate. On the other hand, the ester compounds ofwhich the number of carbon atoms of 29 or more are poor in practicalvalue. In any event, R may be branched or ringed.

The ester compounds of which the number of carbon atoms of R' is 9 ormore are inferior in compatibility with polyolefin resin, and theimprovement in the dispersion and affinity of medium polymer is small.Examples of such an ester compound are bytyl stearate and stearylstearate.

Preferable ester compounds are esters of one or more of alcohols oflauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol,eicosyl alcohol, ceryl alcohol, triacontyl alcohol, isostearyl alcohol,butylcyclohexyl alcohol, etc., and one or more of fatty acids of aceticacid, propionic acid, caproic acid, etc.

The light-shielding material may be either organic material or inorganicmaterial. In order to avoid adverse affects upon photographic propertiesof photographic photosensitive material, strongly acidic or stronglyalkaline materials are unsuitable. Light-shielding materials which donot affect adversely photographic properties and have excellentdispersibility can easily be selected from commercial goods by theteaching of references or several simple tests. The light-shieldingmaterial is added in order to ensure light-shielding and so on .

Representative examples of the light-shielding material are shown below.

Inorganic Compounds:

Oxides . . . silica, diatomaceous earth, alumina, titanium oxide,calcium oxide, iron oxide, zinc oxide, magnesium oxide, antimony oxide,barium ferrite, strontium ferrite, berylium oxide, pumiice, pumiceballoon, alumina fiber, etc.

Hydroxides . . . aluminum hydroxides, magnesium hydroxides, calciumhydroxide, basic magnesium carbonate, etc.

Carbonates . . . calcium carbonate (ground, soft, colloid), magnesiumcarbonate, dolomite, dawsonite, etc.

Sulfates, sulfites . . . calcium sulfate, barium sulfate, ammoniumsulfate, calcium sulfite, etc.

Silicates . . . talc, clay, mica, asbestos, glass fiber, glass baloon,glass bead, calcium silicate, montmorillonite, bentonite, zeolite, etc.

Carbons . . . carbon black, graphite, carbon fiber, carbon hollow bead,etc.

Others . . . iron powder, copper powder, lead powder, tin powder,stainless steel powder, peaorl pigment, aluminum powder, molybdenumsulfide, boron fiber, silicon carbide fiber, brass fiber, potassiumtitanate, lead titanate zirconate, zinc borate, barium metaborate,calcium borate, sodium borate, aluminum paste, etc. Preferable packagingmaterials for a photographic photosensitive material contain one or morelight-shielding materials selected from the above inorganic materialsbecause of ensuring heat resistance, good photographic properties andcomplete light-shielding. In view of the above points, preferableinorganic light-shielding materials have a specific gravity of 1.5 to 8,preferably 1.6 to 7, a hardness (Mohs' hardness) of 1.0 to 9.5,preferably 1.1 to 8, a pH of 4.5 to 9.5, preferably 5 to 9, a heatresistance of 100° C. or more, preferably 105° C. or more, a meanparticle size of 10 μm or less, preferably 9 μm or less, a refractiveindex of 1.50 m or more, preferably 1.55 or more, a DBP oil absorptionvalue of 10 ml/100 g or more. Particularly preferable inorganiclight-shielding materials have a specific gravity of 1.7 to 6, ahardness of 1.2 to 7, a pH of 5.5 to 8.5, a heat resistance of 110° C. amean particle size of 8 μm or less, a refractive index of 1.60 or more,a DBP oil absorption value of 15 ml/100 g or more. Measuring methods ofrespective properties are described later.

Organic Compounds: wood flour such as pine, oak and sawdust, husk fibersuch as almond, peanut and chaff, colored various fibers such as cotton,jute, paper piece, cellophane piece, nylon fiber, polypropylene fiber,various starch (containing modified starch, surface-treated starch,etc.), aromatic polyamide fiber, organic pigments generally used forcoloring plastics, such as azo pigments, phthalocyanine pigments,quinacridone pigments, anthraquinone pigments, dioxazine pigments,perillene pigments, indigo pigments and indanthrene pigments, etc.

Preferable ones are black pigments, such as carbon black, graphite, ironblack, phthalocyanine, aniline black, titanium oxide nitride, CuO--Mn₂O₃ --Fe₂ O₃ pigments and CuO--Cr₂ O₃ --Fe₂ O₅ pigments, and bluepigments, such as Ultramarine Blue, Prussian Blue and Cobalt Blue, whichare light-absorptive light-shielding materials, because of having agreat light-shielding ability and of functioning so as to preventphotographic photosensitive material from fogging caused by light-pipingor irregular reflection.

Among these light-shielding materials, various carbon blacks arepreferable, because dispersibility of carbon black is improved byadsorbing lubricant, surfactant, etc. on the surface or carbon black,and thereby, bleeding out of lubricant, etc. can be decreased.

Carbon blacks are divided into gas black, furnace black, channel black,anthracene black, acetylene black, Ketjen carbon black, thermal black,lamp black, vegetable black and animal black according to their origin.Among these, furnace carbon black is preferable in terms oflight-shielding character, low cost improvement in physical strength andno adverse affect upon photographic properties. On the other hand, sinceacetylene black concluctive carbon black, graphite and Ketschen carbonblack which is modified by-produced carbon black have an antistaticcharacter, they are also preferable, although they are expensive. Theymay be blended with furnace black in order to improve its character.Although, there are various blending method, such as dry coloring,liquid coloring, paste color, masterbatch pellets, compound colorpellets and granular color pellets, the masterbatch method usingmasterbatch pellets is preferred in view of cost and less contaminationof the working place. Japanese Patent KOKOKU No. 40-26196 discloses amethod of making a masterbatch of polymercarbon black by dissolving thepolymer in an organic solvent and dispersing the carbon black into thesolution. Japanese Patent KOKOKU No. 43-10362 discloses another methodof making a masterbatch by dispersing the carbon black intopolyethylene.

Particularly preferable carbon blacks for the packaging material for aphotographic photosensitive material have a pH (JIS K 6221) of 6 to 9,preferably pH 6.5 to 8.5, particularly preferably 6 to 8, a meanparticle size (measured by an electron microscope) of 10 to 120 mμ,preferably 12 to 70 mμ, particularly preferably 15 to 50 mμ, and amongthem, the most preferred is furnace carbon black having a volatilecomponent content (JIS K 6221) of not more than 3.5%, preferably no morethan 1.5%, and a DBP oil absorption value (JIS K 6221) of not less than50 ml/100 g, preferably more than 70 mg/100 g, in view of no 20occurrence of fogging, rare occurrence of photosensitivity deviation andgreat light-shielding ability. Moreover, when it is blended inpolyolefin resin injection molded articles, polystyrene resin injectionmolded articles, L-LDPE resin films, etc. lumps of carbon black and fisheyes rarely occur, and pinholes also rarely occur in injection moldedarticles and light-shielding films. Channel black is not preferredbecause of containing mostly volatile components of more than 5.0%, ofbeing acidic having mostly a pH 3, and of frequently inducing foggingand abnormal sensitivity on photographic photosensitive materials, aswell as of being expensive. Lamp black has mostly pH 5.0 or less, andadversely affects photographic properties. Accordingly, even when it isnecessary to use, a material capable of reacting with or adsorbingsubstances which adversely affect photographic properties must be usedtogether with the carbon blacks, or usable carbon black must be selectedby a preliminary test. Concerning sufur components, unless the contentis 0.9% or less, preferably 0.7% or less, measured by ASTM D-1619-60,photographic properties are occasionally adversely affected, such as theoccurrence of fogging or abnormal sensitivity. Since free sulfurcomponents especially adversely affect photographic properties ofphotographic photosensitive materials, it is preferable to select carbonblacks having a free sulfur content of 0.1% or less, preferably 0.05% orless.

In order to improve wear resistance and reinforcing ability, preferredcarbon blacks have an iodine adsorption amount (JIS K 6221) of 20 mg/gor more, preferably 30 mg/g or more, particularly preferably 35 mg/g ormore, and a dibutylphthalate (DBP) oil absorption value (JIS K 6221) of50 ml/100 g or more, preferably 60 ml/100 g or more, particularly 70ml/100 g or more.

When taking photographic properties, dispersibility into thermoplasticresin, cost, light-shielding ability, prevention of resin deterioration,prevention of physical strength degradation of resin, stableavailability, etc. into consideration, the most suitable carbon black isfurnace carbon black having a pit 6 to 9, a mean particle size of 12 to70 mμ and the above iodime adsorption amount and DBP oil absorpationvalue. As conductive carbon blacks, particularly preferred is furnacecarbon black which does not affect adversely photographic properties, isdispersible almost uniformly into the thermoplastic resin compositionblended with the organic compounds having a number average molecularweight of less than 10,000, can render the surface specific resistance 1the logarithmic mean value of the surface specific resistances at 10parts of a sheet to be tested cut into a square having a side of 12 cmmeasured by using a digital multimeter (Takeda Riken) wherein thedistance between both electiodes was adjusted to 1 cm) to 10 ¹² Ω orless, and has a mean particle size of 12 to 50 mμ, a DBP oil absorptionvalue of 100 ml/100 g or more and a pH of 6-8. Particularly preferableone is furnace carbon black having a DBP oil absorption value of 250ml/100 g or more in view of imparting high conductivity by blending asmall amount.

As the preferable light-shielding materials, inorganic pigments having arefractive index measured by the Larsen oil immersion method of not lessthan 1.50, preferably not less than 1.55, various metal powders, metalflakes, metal pastes, metal fibers, and carbon fiber are next to carbonblack. Representative examples are titanium oxide of the rutile type(2.76), titanium oxide of the anatase type (2.52), silicon carbide(2.67), zinc oxide (2.37), antimony oxide (2.35), lead white (2.09),zinc white (2.02), lithopone (1.84), zircon (1.80), corundum (1.77),spinel (1.73), apatite (1.64), baryta powder (1.64), calcium carbonate(1.58), talc (1.58), calcium sulfate (1.56), silicic anhydride (1.55),silica powder (1.54), magnesium hydroxide (1.54), basic magnesiumcarbonate (1.52), magnesite (1.62), dolomite (1.59), alumina (1.50), andthe like. The number in parenthesis indicates refractive index.Particularly preferable light-shielding materials have a refractiveindex of not less than 1.56, more preferably not less than 1.60. On theother hand, since calcium silicate (1.46), diatomaceous earth (1.45),hydrous silicate (1.44) and the like have a refractive index of lessthan 1.50, they are unsuitable, because of a small light-shieldingability. As a result it is necessary to blend in quantity, and thereby,lump generation increases.

Recently, X-ray checking apparatus is used for baggage inspection at airport. When a high sensitivity photographic film having a sensitivity ofISO photographic speed 400 or more is passed through the X-ray checkingappartus, fogging is liable to occur on the photographic film by X-ray.To blend a light-shielding material having a specific gravity of notless than 3.1, preferably not less than 3.4 particularly preferably notless then 4.0, is preferable for preventing the occurrence of fogging bythe X-ray.

The light-shielding material having X-ray-shielding ability as well aslight-shielding ability has a specific gravity of not less than 3.1,preferably not less than 3.4, particularly preferably not less than 4.0,and the form may be any form, such as pigment, powder, flake, whisker orfiber. Examples of the light-shielding material having X-ray-shieldingability are silicon carbide, barium sulfate, molybdenum disulfide) leadoxide (lead white), iron oxide, titanium oxide, magnesium oxide, bariumtitanate, copper powder, iron powder, brass powder, nickel powder,silver powder, lead powder, steel powder, zinc powder, tungsten whisker,silicon nitride whisker, copper whisker, iron whisker, nickel whisker,chrominum whisker, stainless steel powder and whisker, magnesite,aptite, spinel, corundum, zircon, antimony trioxide, barium carbonate,zinc white, chromium oxide, tin powder, their mixtures, etc.

Particularly preferable ones are zircon, corundum, barium sulfate,barium chloride, barium titanate, lead powder, lead oxide, zinc powder,zinc white, tin powder, stainless steel powder, stainless steel whisker,iron oxide, tungsten whisker, nickel whisker, etc. Preferablelight-shielding materials have a refractive index of not less than 1.50and a specific gravity of not less than 3.1, more preferably arefractive index of not less than 1.56 and a specific gravity of notless than 3.4.

A suitable content of the X-ray-shielding light-shielding material is 5to 80 wt. %, preferably 10 to 70 wt. %, particularly preferably 20 to 60wt. %, in view of the balance among X-ray-shielding ability,moldability, physical strength, appearance, cost, etc. In order not toaffect adversely photographic photosensitive materials and not todegrade film moldability, the X-ray-shielding light-shielding materialis used preferably in a state that weight loss on drying at 100° C. for5 hours is not more than 2 wt. %, preferably not more than 1 wt. %,particularly preferably not more than 0.5 wt. %. The X-ray-shieldinglight-shielding material can be made in this state by using at least oneof washing, refining, heating, evacurating and surface-treating toremove volatile component of 100° C. or less or to prevent adsorption ofmoisture, etc. As oil-absoptive inorganic pigment having a function ofadsorbing lubricant, antioxidant and organic nucleating agent, which areliable to bleed out, deodorant, agent imparting fragrance, oxygenscavenger, etc.; there are zinc white (52), asbestine (50), clay (51),titanium dioxide (56), kaolin (60), talc (60), carbon black (not lessthan 60), activated carbon and the like. The number in parenthesisindicates oil absorption value (ml/g) measured by JIS K 6221, A method.

The metal powder includes metal paste, and examples are aluminum powder,aluminum paste, copper powder, stainless steel powder, iron powder,nickel powder, brass powder, silver powder, tin powder, zinc powder,steel powder and the like.

As the aluminum powder including aluminum paste, aluminum powder ofwhich the surface is coated with a surface-coating material and aluminumpaste from which low volatile components are removed and then kneadedwith a thermoplastic resin are preferred. The paste of aluminum powderis produced by adding a liquid medium such as mineral spirits or and asmall amount of a higher fatty acid such as stearic acid or oleic acidto form a paste at the production of aluminum powder according to aknown method such as using a ball mill, a stamp mill or an atomizer. Thealuminum paste is kneaded together with a thermoplastic resin, such asan aromatic monovinyl resin, such as polystyrene resin orrubber-containing polystyrene resin, a polyolefin thermoplastic resin,such as various polypropylene resins, various polyethylene resins,acid-modified resins, EVA resin, EEA resin or EAA resin, dispersingagent, such as low molecular weight polyolefin resin, paraffin wax,tackifier and metallic soap (fatty acid metal salt), etc. under heat,and volatile components mainly mineral spirits and white spirits areremoved by heat, a vacuum pump or the like up to the low volatilecomponent of not more than 3%, preferably not more than 1%, particulalrypreferably not more than 0.5%. This product is preferably used asaluminum paste compound resin or aluminum paste masterbatch resin. Thealuminum paste masterbatch resin is preferable because noxious odors andadverse influences upon the photographic photosensitive materials areeliminated. In order to eliminate noxious odor and adverse influencesupon the photographic photosensitive materials, the content of mineralspirits should be less than 0.1 wt. %. When the aluminum paste contentof the molded article is made 2 wt. 5 by using a masterbatch resincontaining 40 wt. % of aluminum paste and 1.0 wt. % of mineral spirits,one part by weight of the masterbatch resin is blended with 19 parts byweight of the natural resin for dilution (thermoplastic resin notcontaining a light-shielding material). Since part of the mineralspirits evaporates during molding, the final content of the mineralspirits is less than 0.05 wt. %. The aluminum powder includesmicroflakes produced from aluminum foil which is crushed by a ball millor a stamp mill, in addition to typical aluminum powder manufactured byatomization, dropping on a rotary disc or evaporation from meltedaluminum. Since aluminum powder simplex is unstable and inferior inuniform dispersion into thermoplastic resin, it is atabilized by a knowntreatment.

A suitable content of the light-shielding material is 0. 01 to 30 wt. %in total in order to ensure qualities as goods, photographic properties,moldability and economical view point of the packaging material for aphotographic photosensitive material of the invention, but it variesaccording to light-shielding ability. In the case of carbon black andaluminum powder excellent in light-shielding ability, a suitable contentis 0.05 to 20 wt. %, preferably 0.1 to 10 wt. %, particularly preferably0.2 to 7 wt. % in total. When the content is less than 0.01 wt. %,unless the thickness of the packaging material is increased greatly,fogging occurs due to insufficient light-shielding ability. Thethickening of the packaging material results in the retardation ofmolding speed due to lengthening cooling time, and the cost increases bythe increase of resin. When the content exceeds 30 wt. %, dispersibilitybecomes worse to generate microgrits (lumps) which induces pressuremarks and abrasion on photographic photosensitive materials. Moreover, awater content of the packaging material increases by the increase ofwater adsorbed on carbon black, and adversely affects photographicproperties, such as fogging, sensitivity deviation and abnormalcoloring, upon photographic photosensitive materials. Furthermore,moldability of the packaging material is degraded to induce theoccurrence of foaming, silver streaks, pinholes short shot or the like,appearance is degraded, and physical strength decreases.

It is preferable to coat the surface of a light-shielding material,preferably carbon black, aluminum powder (including aluminum paste),inorganic pigment having a refractive index of not less than 1.50,inorganic pigment having a specific gravity of not less than 3.4 orinorganic pigment having an oil absorption value of not less than 50ml/100 g, by surface-coating material, in order to improve thedispersibility into resin and the resin fluidity, to prevent thegeneration of volatile substances harmful to photographic properties, todecrease hygroscopicity, to prevent fouling of die lip, and the like.The surface-coating materials are also useful as the surface-coatingmaterial of inorganic or organic nucleating agent, hydrous double saltof hydrotalcite, etc. described later.

Representative coatings by the surface-coating material are as follows:

(1) Using a coupling agent:

Coated with a coupling agent containing azidosilane compound (disclosedin Japanese Patent KOKAI No. 62-32125).

Coated with a silane coupling agent.

Coated with a titanate coupling agent.

(2) Coated by depositing silica followed by depositing alumina.

(3) Coated with higher fatty acid metal salt, such as zinc stearate,magnesium stearate or calcium stearate.

(4) Coated with surfactant, such as sodium stearate, potassium searateor hydroxyethylene dodecylamine.

(5) Coated by reacting barium sulfide aqueous solution with sulfuricacid aqueous solution in the presence of an excess amount of barium ionto produce barium sulfate having a mean particle size of 0.1 to 2.5 μm,adding alkaline silicic acid solution thereto to deposit barium silicateon the surface of the barium sulfate, and depositing hydrous silica onthe surface of the barium sulfate produced by the decomposition of thebarium silicated by adding mineral acid to the slurry.

(6) Coated with a composition consisting of one or more of the oxidesselected from hydrated oxides of metal, such as titanium, aluminum,cerium, zinc, iron, cobalt or silicon, and oxides of metal, such astitanium, aluminum, cerium, zinc, iron, cobalt or silicon.

(7) Coated with a polymer having one or more reactive groups selectedfrom aziridine group, oxiazoling group and N-hydroxyalkylamide group.

(8) Coated with polyoxyalkylene amine compound.

(9) Coated with cerium, iron, selected acid amion and alumina.

(10) Coated with alkoxy titanium derivative having α-hydroxycarboxylicacid residue as substituent.

(11) Coated with polytetrafluoroethylene.

(12) Coated with polydimethylsiloxane or modified silicone.

(13) Coated with phosphate ester compound.

(14) Coated with divalent to tetravalent alcohol.

(15) Coated with olefin wax, such as polyethylene wax or polypropylenewax.

(16) Coated with hydrous aluminum oxide.

(17) Coated with silica of zinc compound consisting of zinc chloride,zinc hydroxide, zinc oxide, zinc sulfate, zinc nitrate, zinc acetate orzinc citrate of a combination thereof.

(18) Coated with polyhydroxy saturated hydrocarbon.

Preferable coatings are the above (1), (3), (12), (14), (15), (16) andorganic chelate compounds, various antistatic agents, lubricants,dripproofing agents and surfactants, because of rare adverse effect uponphotographic photosensitive materials, such as fogging, and beingexcellent in the improvement in the dispersibility of light-shieldingmaterial, in the decrease of lump generation, and in the improvement inresin fluidity.

Particularly suitable coatings are esters of an aliphatic monocarboxylicacid and a monovalent aliphatic alcohol in an amount of 0.001 to 2 wt.%. The ester decreases motor load, and improves the dispersibility oflight-shielding material and moldability to render the appearance ofmolded articles beautiful. The ester is composed of an aliphaticmonocarboxylic acid having a number of carbon atoms of 20 to 40,preferably 25 to 35 and a monovalentaliphatic alcohol having a number ofcarbon atoms of 20 to 40, preferably 25 to 35. Examples of the aliphaticmonocarboxylic acid are montanic acid, melissic acid, cerotic acid,lacceric acid and the like. Examples of the monovalent aliphatic alcoholare montyl alcohol, melissyl alcohol, lacceryl alcohol, ceryl alcoholand the like. The above esters are also very excellent as thesurface-coating material of the light-shielding material because of theimprovement in the fluidity of thermoplastic resin and uniformblendability. Moreover, when they are used for coating the surface ofinorganic or organic nucleating agent as the dispersing agent, variousexcellent effects are exercised, such as the prevention of dusting andbleeding out, and the improvement in dispersibility and resin fluidityand the like.

A suitable coating amount is 0.001 to 10 wt. %, preferably 0.005 to 5wt. %, more preferably 0.01 to 3 wt. %, particularly preferably 0.05 to1.5 wt. %, against light-shielding material, such as carbon black oraluminum powder. When the coating amount is less than 0.001 wt. %, thecoating effect is insufficient. When the coating amount exceeds 10 wt.%, bleeding out with time increases. Moreover, screw slip occurs thatresults in a variation of the amount of ejected resin.

A suitable total sulfur content (ASTM D-1619) of the above compositelight-shielding material is not more than 1 %, preferably not more than0.8%, particularly preferably not more than 0.5%. A suitable free sulfurcomponent is not more than 150 ppm, preferably not more than 50 ppm,particularly preferably not more than 30 ppm, and an ash contentaccording to ASTM D-1506 is not more than 0.5%, preferably not more than0.4%, particularly preferably not more than 0.3%. A suitable aldehydecompound content is not more than 0.2%, preferably not more than 0.1%,particularly preferably not more than 0.05%, in order to avoid adverseeffects upon photographic properties. Since cyanides also adverselyaffect photographic properties of photographic photosensitive materials,it is suitable that the hydrogen cyanide quantity determined by the4-pyridine-carboxylic acid pyrazolone absorption photometry is not morethan 20 ppm, preferably not more than 10 ppm, particularly preferablynot more than 5 ppm, converted to the weight of light-shieldingmaterial.

A suitable blending amount of the light-shielding material in apackaging material for a photographic photosensitive material is 0.01 to30 wt. %, preferably 0.05 to 20 wt. %, more preferably 0.1 to 10 wt. %,particularly preferably 0.2 to 7 wt. %. When a material colored bylight, such as vitamin E and photosensitive resins is combined,combination effects greatly exhibit which are improvement inlight-shielding ability by the increase of color density, andaccordingly, the blending amount of light-shielding material can bedecreased resulting in less degradation of physical strength,improvement in melt salability, moldability and resin fluidity.Particularly, in the case of a thickness of 100 μm or less, a suitableblending amount of light-shielding material is 0.1 to 20 wt. %,preferably 0.5 to 15 wt. %, more preferably 0.7 to 10 wt. %,particularly preferably 1 to 7 wt. %, in view of ensuringlight-shielding and physical strength.

The light-shielding material may be a mixture of carbon black and agraphite interlaminar compound. The graphite interlaminar compound is aninterlaminar compound of graphite and a compound capable of imparting ahigh conductivity to the graphite, such as an alkali metal, e.g.potassium, arsenic pentafluoride, antimony pentafluoride or nitric acid,and the compound capable of imparting a high conductivity to thegraphite particles wides a space between layers of praphite having acrystalline structutre and is dispersed thereinto. The graphiteinterlaminar compound can be obtained relatively easily by contactinggraphite particles with gas of the compound capable of imparting a highconductivity. A suitable mean particle size of the graphite interlaminarcompound is 5 μm or less, preferably 3.5 μm or less, more preferably 2μm or less, most preferably 1 μm or less. The mean particle size ofcarbon black is necessary to be smaller than the mean particle size ofthe graphite interlaminar compound, and is preferably 1/3 or less or themean particle size of the graphite interlaminar compound, morepreferably 1/5 or less, furthermore preferably 1/10 or less, mostpreferably 1/20 or less.

The blending ratio of the graphite interlaminar compound to carbon blackin the above mixture is 1:9 to 9:1, preferably 2:8 to 8:2, morepreferably 3:7 to 8:2, most preferably 5:5 to 7:3. By using the speciallight-shielding thermoplastic resin film is made excellent in completelight-shielding material and antistic ability without affectingadversely photographic properties, and it can be put to practical use asa packaging material for a photographic photosensitive material even ina single layer film.

It is preferable to blend a lubricant in order to improve packagingability, peeling resistance, antistatic ability, and moldability ofthermoplastic resin film.

Examples of the lubricant are as follows:

(I) Fatty acid amide lubricants

(1) Saturated fatty acid amide lubricants:

1 Behenic acid amide lubricants: "DIAMIDE KN" (Nippon Kasei ChemicalCo., Ltd.)

2 Stearic acid amide lubricants: "ARMIDE HT" (Lion), "ALFLOW S-10"(Nippon Oil and Fats Co., Ltd.), "FATTY AMIDE S" (Kao Corp.), "NEWTRON2" (Nippon Fine Chemical Co., Ltd.), "DIAMID 200" and "DIAMIDE AP-1"(Nippon Kasei Chemical Co., Ltd.), "AMIDE S" and "AMIDE T" (Nitto KagakuK.K.), etc.

(2) Hydroxystearic acid amide lubricants:

1 Palmitic acid amide lubricants: "NEWTRON S-18" (Nippon Fine ChemicalCo., Ltd.), "AMIDE P" (Nitto Kagaku K.K.), etc .

2 Lauric acid amide lubricants: "AMIDE C" (Lion Akzo Co., Ltd.),"DIAMID" (Nippon Kasei Chemical Co., Ltd.), etc.

(3) Unsaturated fatty acid amide lubricants:

1 Erucic acid amide lubricants: "ALFLOW P-10" (Nippon Oil and Fats Co.,Ltd.), "NEWTRON-S" (Nippon Fine Chemical Co., Ltd.), "LUBROL" (I.C.I.),"DIAMID L-200" (Nippon Kasei Chemical Co., Ltd.), etc.

2 Oleic acid amide lubricants: "ARMOSLIP-CP" (Lion Akzo Co. , Ltd.),"NEWTRON" and "NEWTRON E-18" (Nippon Fine Chemical Co., Ltd.), "AMIDE-O"(Nitto Kagaku K.K.),"DIAMID O-200" and "DIAMID G-200" (Nippon KaseiChemical Co., Ltd.), "ALFLOW E-10" (Nippon Oil and Fats Co., Ltd),"FATTY AMIDE O" (Kao Corp.), etc.

(4) Bisfatty acid amide lubricants

1 Methylenebisbehenic acid amide lubricants: "DIAMID NK BIS" (NipponKasei Chemical Co., Ltd.), etc.

2 Methylenebisstearic acid amide lubricants: "DIAMID 200 BIS" (NipponKasei Chemical Co., Ltd.), "ARMOWAX" (Lion Akzo Co., Ltd.), "BISAMIDE"(Nitto Kagaku K.K.), etc.

3 Methylenebisoleic acid amide lubricants: "LUBRON 0" (Nippon KaseiChemical Co, Ltd.), etc.

4 Ethylenebisstearic acid amide lubricants: "ARMOSLLP EBS" (Lion AkzoCo., Ltd.), etc.

5 Hexamethylenebisstearic acid amide lubricants: "AMIDE 65" (KawakenFine Chemicals Co., Ltd.), etc.

6 Hexamethylenebisoleic acid amide lubricants: "AMIDE 60" (kawaken FineChemicals Co., Ltd.), etc.

(II) Nonionic surfactant lubricants: "ELECTROSTRIPPER TS-2","ELECTROSTRIPPER TS-33" (Kao Corp.), etc.

(III) Hydrocarbon lubricants: liquid paraffin, natural paraffin,microwax, synthetic paraffin, polyethylene wax (number average molecularweight less than 10,000, preferably less than 8,000, particularlypreferably less than 6,000), polypropylene wax (number average molecularweight less than 10,000, preferably less than 8,000, particularlypreferably less than 6,000), chlorinated hydrocarbon, fluorocarbon, etc.

(IV) Fatty acid lubricants: higher fatty acids preferably more than C₁₂,such as caproic acid stearic acid, oleic acid, erucic acid and palmiticacid, hydroxy fatty acids, etc.

(V) Ester lubricants: fatty acid lower alcohol esters, fatty acid polyolesters, fatty acid polyglycol esters, fatty acid fatty alcohol esters,etc.

(VI) Alcohol lubricants: polyols, polyglycols, polyglycerols, etc.

(VII) Fatty acid metal salts (metal soap): compounds of metal, such asLi, Na, Mg, Ca, Sr, Ba, Zn, Cd, Al, Sn, Pb with a fatty acid having anumber of carbon atoms of 6 to 50 preferably 10 to 40, particularlypreferably 10 to 30, such as caproic acid, caprylic acid, capric acid,myristic acid, lauric acid, stearic acid, succinic acid, behenic acid,linolic acid, stearyl lactic acid, lactic acid, phthalic acid, benzoicacid, hydroxystearic acid, montanic acid, ricinoleic acid, naphthenicacid, oleic acid, palmitic acid or erucic acid. Preferred are magnesiumstearate, calcium stearate, zinc stearate, magnesium oleate, etc.

(VIII) Partially saponified montanate esters:

(IX) Silicone lubricants dimethylpolysiloxanes and modified versionsthereof in various grades (Shin-Etsu Silicone, Toray Silicone).

Particularly, various silicone oils are preferable, because of not onlyexhibiting the improvement in resin fluidity, lubricity, etc. but also,when they are used together with a light-shielding material, exhibitingunexpected effects, such as the improvement in the dispersibility oflight-shielding material and the increase of haze (ASTM D-1003) byrendering resin turbid resulting in the improvement in coloring powerand light-shielding ability.

The above silicone oil has preferably a viscosity at ordinarytemperature (25° C. ) of 50 to 100,000 centistokes, preferably 1,000 to60,000 centistokes, more preferably 5,000 to 30,000. When the viscosityis less than 50 centistokes, the silone oil adversely affectsphotographic properties, and bleeding out becomes a problem. When theviscosity exceeds 100,000 centistokes, difficulty occurs in handlingbecause of too viscous.

Examples of silicones and modified versions thereof are those havingmodified siloxane bonds such as polydimethylsiloxane andpolymethylphenylsiloxane, olefin-modified silicone, amide-modifiedsilicone, amino-modified silicone, dimethylpolysiloxane, amino-modifiedsilicone, carboxyl-modified silicone, α-mehylstyrene-modified silicone,polyether-modified silicone modified with polyethylene glycol,polypropylene glycol, etc., olefin/polyether-modified silicone,epoxy-modified silicone, alcohol-modified silicone, etc. Among them,olefin-modified silicone, polyether-modified siliconedimethylpolysiloxane, amide-modified silicone, carboxyl-modifiedsilicone, and olefin/polyether-modified silicone are preferable forpackaging materials for a photographic photosensitive material becauseof rare adverse affects upon photographic properties and a greatlubricating effects. The silicone oil improves friction coefficient of amolding material, such as a resin sheet in heated conditions, decreasessliding resistance generated during hot plate sealing in an automaticpackaging machine an prevents the occurrence of wrinkling. Thereby, thesilicone oil provides a resin film which has a beautiful appearance, ahigh sealability, and adhesion to an article to be packaged withoutsagging. It also prevents the degradation of gloss by sliding to form afine sealed portion. In the case of using silicone oil, frictioncoefficient at high temperature can be not more than 1.4 for slidingheat seal. In the case of a packaging material for a photographicphotosensitive material composed of injection molded articles, sincelight-shielding ability is increased, blending amount of light-shieldingmaterial can be decreased. As a result, various properties, such asphysical strength, injection moldability and appearance can be improved.Particularly, when a rubber-modified polystyrene resin modified with asynthetic resin (high impact polystyrene resin according to JIS) isblended with silicone oil, blending effects, such as the improvement inlubricity, wear resistance, light-shielding ability, etc., are greatlyexhibited.

The above effects can further be increased by further blending a naturalor synthetic wax, a caster oil ethylene oxide adduct, oxidativesynthetic wax, a higher fatty acid alkyl ester, a polyol alkylateethylene oxide adduct, a fatty amide, a bis fatty amide a fatty acidmetal salt, etc., having a softening point of 70° to 140° C., togetherwith the above silicone oil. A suitable blending amount of the abovewax, etc. is 10 to 200 parts, preferably 30 to 180 parts, particularlypreferably 50 to 150 parts per 100 parts of the silicone oil. Bycombining the above wax, etc., stick slip at 100° C. or less which isliable to occur in the case of using merely silicone oil can beprevented, slip from various metal guide plates of an automaticpackaging machine is rendered smooth, and packaging troubles can beprevented. Furthermore, slip under pressurized high temperatureconditions can also be improved.

The compatibilizing agent is a material capable of compatibilizing twoor more thermoplastic resins, when a novel property or performance notexisting in a single thermoplastic resin is exhibited by combining samekind thermoplastic resins which are different in properties, two or morekinds thermoplastic resins, recycled thermoplastic resin and virginresin (thermoplastic resins not used in a form of a molded article),masterbatch thermoplastic resin containing light-shielding material in ahigh concentration and thermoploastic resin for dilution (the resinblended with the masterbatch resin) or combinations thereof.

A suitable blending amount of the compatibilizing agent is 1 to 70 wt.%, preferably 2 to 50 wt. %, more preferably 3.5 to 40 wt. %,particularly preferably 5 to 35 wt. %, in view of not degrading physicalstrength while achieving the above objects and in a practical viewpoint.When the content is less than 1 wt. %, the improvement in physicalstrength, appearance and compatibility cannot be achieved effectively.When the content exceeds 70 wt. %, the compatibilizing agent is possibleto affect adversely photographic photosensitive materials, and moreover,raises the manufacturing cost.

As the compatibilizing agent, there are non-reactive compatibilizingagents and reactive compatibilizing agents.

Examples of non-reactive compatibilizing agent:

Styrene-ethylene-butadienen block copolymer resin

Polyethylene-polystyrene graft copolymer resin

Polyethylene-polymethyl methacrylate graft copolymer resin

Polyethylene-polymethyl methacrylate block copolymer resin

Ethylene-propylene-diene copolymer resin

Ethylene-propylene copolymer resin

Polystyrene-low density homopolyethylene graft copolymer resin

Polystyrene-high density homopolyethylene graft copolymer resin

Hydrogenatedstyrene-butadiene copolymer resin

Styrene-ethylene/butadiene-styrene copolymer resin

Styrene-butadiene-styrene copolymer resin

Chlorinated polyethylene resin

Polypropylene-polyamide graft copolymer resin

Polypropylene-ethylene-propylene-diene copolymer resin

Polystyrene-polyethyl acrylate graft copolymer resin

Polystyrene-polybutadiene graft copolymer resin

Polystyrene-polymethyl methacrylate block copolymer resin etc.

Examples of reactive compatibilizing agent:

Maleic anhydride-induced ethylene-propylene copolymer resin

Maleic anhydride-induced styrene graft copolymer resin

Maleic anhydride-induced styrene-butadiene-styrene copolymer resin

Maleic anhydride-induced styrene-ethylene-butadiene-styrene copolymerresin

Ethylene-glycidyl methacrylate copolymer resin

Ethylene-glycidyl methacrylate-styrene graft copolymer resin

Ethylene-glycidyl methacrylate-methyl methacrylate graft copolymer resin

Maleic anhydride-grafted polypropylene copolymer resin, etc.

Representative examples of a plasticizer usable for the invention aredescribed below.

(1) Phthalic acid plasticizer dibutyl phthalate, diheptyl phthalate,dioctyl phthalate, diisodecyl phthalate, butyl lauryl phthalate,ditridecyl phthalate, butyl benzyl phthalate, butyl phthalyl butylglycolate, etc.

(2) Phosphoric acid plasticizer tricresyl phosphate, trioctyl phosphate,etc.

(3) Fatty acid plasticizer tri-n-butyl citrate, dioctyl adpate, dioctylazelate, dioctyl sebacate, methyl acetyl ricinoleate, etc.

(4) Epoxy plasticizer alkyl epoxy stearate,4,5-epoxytetrahydrodiisodecyl phthalate, etc.

(5) Other plasticizer chlorinated paraffin, polyester, sucroseoctacetate, etc .

A suitable blending amount of the plasticizer is 0.01 to 10 wt. %,preferably 0.05 to 7 wt. %, particularly preferably 0.1 to 5 wt. %. Whenthe blending amount is less than 0.01 wt. %, the blending effects of theimprovement in the uniform dispersibility of light-shielding materialand in the blocking adhesion is insufficient. When the blending amountexceeds 10 wt. %, screw slip occurs in an extruder resulting in thevariation of ejected resin amount.

Antistatic agent applicable to the invention includes:

Nonionic Antistatic Agent:

Alkylamine derivatives:

Polyoxyethylene alkyl amine, tertiary amine e.g. laurylamine,N,N-bis(2-hydroxyethyl cocoamine, N-hydroxyhexadecyl-di-ethanolamine,N-hydroxyoctadecyl di-ethanolamine, etc.

Fatty acid amide derivatives:

Oxalic acid-N,N'-distearylamide butyl ester, polyoxyethylene alkylamide, etc.

Ethers:

Polyoxyethylene alkyl ether, RO(CH₂ CH₂)_(n) H polyoxyethylene alkylphenyl ether, etc.

Polyol esters:

Glycerine fatty acid esters (mono, di or tri-glyceride of stearic acid,hydroxystearic acid, etc.), sorbitan fatty acid esters,1-hydroxyethyl-2-dodecylglyoxazoline, etc.

Anionic Antistatic Agent:

Sulfonates:

Alkyl sulfonate (RSO₃ Na), alkylbenzene sulfonate, alkyl sulfate (ROSO₃Na), alkyl aryl sulfate, etc.

Phosphate esters:

Alkyl phosphate, etc.

Cationic Antistatic Agent:

Cationic amides:

Quaternary ammonium salts:

Quaternary ammonium chloride, quaternary ammonium sulfate, quaternaryammonium nitrate, e.g. stearamide propyl-dimethyl-β-hydroxyethylammonium nitrate, etc.

Ampholytic Antistatic Agent:

Alkyl betaines:

Imidaxolines:

Alkyl imidazolines:

Metal salts:

(RNR'CH₂ CH₂ CH₂ NCH₂ COO)₂ Mg {R≧C, R'═H or (CH₂)_(m) COO--,}etc.

Alkyl alanines:

Conductive resin:

Polyvinylbenzyl cation, polyacrylic acid cation, etc.

Various known antistatic agents can be used in the invention byselecting type, adjusting blending amount or combining other additive(s)so as not to affect adversely photographic properties of photographicphotosensitive materials. For example, they can be selected from variousantistatic agents disclosed on pages 776 to 778 of "Plastic DateHandbook" (published by Kogyo Chosa Kai, those disclosed on pages 123 to151 of "Plastic Data Collection" (published by The Chemical Daily Co.,Ltd., those disclosed in "Taidenboshizai-Kobunshi no Hyomen Kaishitsu(Antistatic Agent-Surface Modification of Polymers), Zohoban (EnlargedSupplement)" (published by Hana Shobo on Mar. 25, 1972).

Among them, nonionic antistatic agents are particularly preferred,because adverse affects upon photographic properties and human body aresmall, and static marks can be prevented remarkably.

A suitable blending amount of the antistatic agent is 0.01 to 10 wt. %,preferably 0.05 to 7 wt. %, particularly preferably 0.1 to 5 wt. %. Whenthe blending amount is less than 0.01 wt. %, the blending effects areinsufficient. When the blending amount exceeds 10 wt. % slip betweenmolten resin and a screw of an extruder is liable to occur resulting inthe variation of ejected resin amount. Moreover, greasiness and bleedingout tend to occur with time.

A dripproofing agent may be blended. The dripproofing agent includesdiglycerine monostearate ester, polyglycerine monopalmitate ester,sorbitan monolaurate ester, sorbitan monoerucate, polyoxyethylenesorbitan fatty acid ester, stearic acid monoglyceride, palmitic acidmonoglyceride, oleic acid monoglyceride, lauric acid monoglyceride,polyoxyethylene nonylphenyl ether, sorbitan sesquipalmitate, diglycerinesesquioleate, sorbitol fatty acid ester, sorbitol fatty acid dibasicacid ester, diglycerine fatty acid dibasic acid ester, glycerine fattyacid dibasic acid ester, sorbitan fatty acid dibasic acid ester,sorbitan palmitate, sorbitan stearate, sorbitan palmitate propyleneoxide 3 moles adduct, sorbitan palmitate propylene oxide 2 moles adduct,sorbitol stearate, sorbitol stearate ethylene oxide 3 moles adduct,diglycerine palmitate, glycerine palmitate, glycerine palmitate ethyleneoxide 2 moles adduct, etc.

The dripproofing agent functions also to prevent adhesion of dew and toinhibit deposition into white powder of additives liable to bleed out,such as lubricant and antioxidant. Preferable dripproofing agents have acontact angle with water of 45 degrees or less, more preferably 35degrees or less. Besides two or more of water-absorptive material(s),hygroscopic material(s) and dripproofing agent(s) may be combined.

A suitable blending amount of the dripproofing agent is 0.01 to 5 wt. %,preferably 0.05 to 3.5 wt. %, particularly preferably 0.1 to 2.5 wt. %.When the blending amount is less than 0.01 wt. %, fog resistance isinsufficient. Moreover, to inhibit deposition into white powder ofadditives liable to bleed out, such as lubricant and antioxidant isinsufficient. When the blending amount exceeds 5 wt. %, the effectincreased by increasing the blending amount is little. Bleeding out ontothe surface of the molded article withtime increases resulting in thedegradation of quality, such as greasiness and adhesion of dust. Whenthe dust adheres to a photographic film, uneven developing rate troubleoccurs.

It is preferable to provide molded articles containing the dripproofingagent with a surface activation treatment, such as corona discharge,ozone treatment, plasma treatment, etc. because of exhibiting antifogaction and dripproof action more effectively.

The organic nucleating agent usable in the invention includes carboxilicacids, dicarboxylic acids, their salts and anhydrides, salts and estersof aromatic sulfonic acids, aromatic phosphinic acids, aromaticphosphonic acids, aromatic carboxylic acids and their aluminum salts,metal salts of aromatic phosphoric acids, alkyl alcohols having a numberof carbon atoms of 8 to 30, condensation products of a polyhydricalcohol and an aldehyde, and alkylamines. Examples are aluminump-t-butylbenzoate, 1,3-benzylidenesorbitol,1·3,2·4-dibenzylidensorbitol, the di-substituted benzylidene-sorbitolrepresented by the following formula; ##STR3##

In the formula, R₁ and R₂ indicate an alkyl group or an alkoxy grouphaving a number of carbon atoms of 1 to 8 or a halogen, and m and n are0 to 3 and m+n≧1.

metal salts, such as calcium salt and magnesium salt, of stearyl lacticacid, the compounds, such as N-(2-hydroxyethyl)-stearylamine,represented by the following formula; ##STR4##

In the formula, R₃ indicates an alkyl group having a number of carbonatoms of 8 to 30, and k and l are 0 to 10 and k+l≧1.

metal salts, such as lithium salt, sodium salt, potassium salt, calciumsalt and magnesium salt, of 1,2-dihydroxystearic acid, alkyl alcohols,such as stearyl alcohol and lauryl alcohol, sodium benzoate, benzoicacid, and sebacic acid.

Among the organic nucleating agents, sorbitol compounds are preferable.Examples of the sorbitol compound are as follows:

di-(o-methylbenzylidene) sorbitol

o-methylbenzylidene-p-methylbenzylidene sorbitol

di-(m-methylbenzylidene) sorbitol

m-methylbenzylidene-o-methylbenzlidene sorbitol

di-(p-methylbenzylidene)sorbitol

m-methylbenzylidene-p-methylbenzylidene sorbitol

1·3-heptanylidenesorbitol

1·3,2·4-diheptanylidenesorbitol

1·3,2·4-di(3-nonyl-3-pentenylidene)sorbitol

1·3-cyclohexanecarbylidenesorbitol

1·3,2·4-dicyclohexanecarbylidenesorbitol

1·3,2·4-di (p-methylcyclohexanecarbylidene )sorbitol

Aromatic hydrocarbon groups and derivatives thereof

1·3-benzylidenesorbitol

1·3,2·4-dibenzylidene-D-sorbitol

1·3,2·4-di(m-methylbenzylidene)sorbitol

1·3,2·4-di(p-methylbenzylidene)sorbitol

1·3,2·4-di(p-hexylbenzylidene)sorbitol

1·3,2·4-di(l-naphthalenecarbylidene)sorbitol

1·3,2·4-di(phenylaceylidene)sorbitol

1·3·2·4-di(methylbenzylidene)sorbitol

1·3·2·4-di(ethylbenzylidene)sorbitol

1·3·2·4-di(propylbenzyledene )sorbitol

1·3·2·4-di(methoxybenzylidene)sorbitol

1·3·2·4-di(ethoxybenzylidene)sorbitol

1·3·2·4-di(p-methylbenzylidene)sorbitol

1·3·2·4-di(p-chlorobenzylidene)sorbitol

1·3·2·4-di(p-methoxydenzylidene)sorbitol

1·3·2·4-di(alkyldenzylidene)sorbitol

1·3·2·4-di (methylbenzylidene)sorbitol aluminum benzoate, etc.

The nucleating agent is not limited to the above compounds, and anyknown nucleating agent may be employed. Moreover, two or more nucleatingagents may be used simultaneously.

Preferable nucleating agents are organic nucleating agent ofdibenzylidenesorbitol compounds, and the di-substitutedbenzylidenesorbitol compositions described below are particularlypreferable for the polyolefin resins, preferably homopolypropyleneresins, propylene-α-olefin block copolymer resins, propylene-α-olefinrandom copolymer resins, homopolyethylene resins having a density of notless than 0.910 g/cm³ and ethylene-α-olefin copolymer resins having adensity of not less than 0.870 g/cm³, which belong to the crystallineresin, in view of the improvement in Young's modulus, physical strength,rigidity hardness, wear resistance, dimensional accuracy,crystallization rate and molding speed, the decrease of moldingtroubles, and the improvement in foreign odor and blending out which arethe defects of conventional organic nucleating agent.

The di-substituted benzylidenesorbitol composition contains solid powderof the dibenzylidenesorbitol derivative represented by the followinggeneral formula and the following higher fatty acid as the essentialcomponents, and the surface of the solid powder of the dibenzylidenesorbitol derivative is coated with the higher fatty acid. ##STR5##

In the formula, R and R' independently represent an atom or a groupselected from chlorine atom, methyl group and ethyl group, preferablychlorine atom or methyl group.

    CH.sub.3 (CH.sub.2).sub.n COOH

In the formula, n represents a number of 14 to 30, preferably 18 to 27,particularly preferably 20 to 25.

Preferable dibenzylidenesorbitol derivatives of the above generalformula are 1·3,2·4-di(p-methylbenzylidene) sorbitol,1·3,2·4-di(p-ethylbenzylidene)sorbitol,1·3-p-methylbenyilidene-2·4-p-chlorobenzylidenesorbitol,1·3-p-methylbenzylidene-2·4-p-ethylbenzylidenesorbitol,1·3-p-chlorobenzylidene-2·4-p-methylbenzylidensorbitol and the like.Particularly preferable dibenzylidenesorbitol derivatives are1·3,2·4-di(p-methylbenzylidene)sorbitol,1·3-p-methylbenzylidene-2·4-p-chlorobenzylidene sorbitol and1·3-p-chlorobenzylidene-2·4-p-methylbenzylidenesorbitol.

Preferable higher fatty acids are behenic acid, stearic acid andpalmitic acid. Behenic acid is the most preferable, and stearic acid isin the second place.

The particle size of the solid powder of the dibenzylidene sorbitolderivative is not particularly limited, but a particle size distributionof 30 to 100 mesh is preferred.

Preferable organic nucleating agent composition contains 95 to 50 partsby weight, preferably 90 to 50 parts by weight, of thedibenzylidenesorbitol derivative and 5 to 50 parts by weight, preferably10 to 50 parts by weight, of at least one of the higher fatty acidand/or a higher fatty acid compound (fatty acid metal salts, fatty acidamides, etc.) and/or a plasticizer so that the total of both componentsis 100 parts by weight.

The di-substituted dibenzylidenesorbitol can be prepared by adding thesolid powder of the dibenzylidenesorbitol derivative to an aqueousemulsion containing at least one of the higher fatty acid and/or thehigher fatty acid compound and/or the plasticizer in the above ratio,stirring to form a coating layer of at least one of the higher fattyacid and/or the higher fatty acid compound and/or the plasticizer on thesurface of the solid powder of the dibenzylidenesorbitol derivative,filtering out the dibezylidenesorbitol derivative powder coated with atleast one of the higher fatty acid and/or the higher fatty acid compoundand/or the plasticizer, washing followed by drying. The above aqueousemulsion of at least of the higher fatty acid and/or the higher fattyacid compound and/or the plasticizer is prepared by dispersing anorganic solvent solution of at least one of the higher fatty acid and/orthe higher fatty acid compound and/or the plasticizer in a concentrationof 5 to 50 wt. %, preferably 10 to 50 wt. % into water together with asmall amount, such as 1 to 10 parts by weight, preferably 2 to 5 partsby weight, of surfactant. The presence of at least one of the higherfatty acid and/or the higher fatty acid compound and/or the plasticizercoating formed on the surface of the solid powder of thedibenzylidenesorbitol derivative can be confirmed by coloring thecoating using a dye and then observing. In addition, it is alsopreferable to coat the surface of the organic nucleating agent by thesurface coating material for the light-shielding material describedlater, in view of the improvement in dispersibility, etc.

The polyolefin resin, to which the preferable organic nucleating agentcomposition is blended as an additive in order to improve physicalstrength and to decrease bleeding out and odor, includes homopolymersand copolymers of aliphatic monoolefin having a number of carbon atomsof 2 to 6, such as polypropylene resins including powder of thedibenzylidenesorbitol derivative, filtering out the dibezylidenesorbitolderivative powder coated with at least one of the higher fatty acidand/or the higher fatty acid compound and/or the plasticizer, washingfollowed by drying. The above aqueous emulsion of at least of the higherfatty acid and/or the higher fatty acid compound and/or the plasticizeris prepared by dispersing an organic solvent solution of at least one ofthe higher fatty acid and/or the higher fatty acid compound and/or theplasticizer in a concentration of 5 to 50 wt. %, preferably 10 to 50 wt.% into water together with a small amount, such as 1 to 10 parts byweight, preferably 2 to 5 parts by weight, of surfactant. The presenceof at least one of the higher fatty acid and/or the higher fatty acidcompound and/or the plasticizer coating formed on the surface of thesolid powder of the dibenzylidenesorbitol derivative can be confirmed bycoloring the coating using a dye and then observing. In addition, it isalso preferable to coat the surface of the organic nucleating agent bythe surface coating material for the light-shielding material describedlater, in view of the improvement in dispersibility, etc.

The polyolefin resin, to which the preferable organic nucleating agentcomposition is blended as an additive in order to improve physicalstrength and to decrease bleeding out and odor, includes homopolymersand copolymers of aliphatic monoolefin having a number of carbon atomsof 2 to 6, such as polypropylene resins including homopolypropyleneresins and propylene-α-olefin copolymer resins polyethylene resinsincluding low density homopolyethylene resins, high densityhomopolyethylene resins, linear polyethylene (ethylene-α-olefincopolymer) reins and ethylene-propylene copolymer resins and the like,having a number average molecular weight of about 10,000 to 600,000preferably 11,000 to 500,000, more preferably 12,000 to 400,000,particularly preferably 13,000 to 300,000. Particularly, crystallinepolyolefin resins having a high crystallinity are preferable, becauseblending effects of the organic nucleating agent are effectivelyexhibited. A suitable crystallinity is 50% or more, preferably 70% ormore, more preferably 80% or more, most preferably 90% or more. Asuitable molecular weight distribution (weight average molecularweight/number average molecular weight) of the polyolefin resin is 1.5to 20, preferably 2 to 15, more preferably 2.5 to 12, most preferably 3to 10, in view of the balance between to ensure physical strength and toensure moldability. It was found that the blending effect of the organicnucleating agent having a less molecular weight distribution isexhibited more effective. The molecular weight distribution isdetermined by the molecular weight measured by the GPC method. When themolecular weight distribution is less than 1.5, physical strength isvery excellent, and in the case of injection-molded articles,dimensional accuracy is excellent. However, moldability is degraded, andpolymerization is not easy. When the molecular weight distributionexceeds 20, matters opposite to the above occurs.

A suitable blending amount of the di-substituted benzylidenesorbitolcomposition is 0.005 to 5 parts by weight, preferably 0.01 to 3 parts byweight of the di-benzylidenesorbitol derivative coated with at least oneof the higher fatty acid and/or the higher fatty acid compound and/orthe plasticizer per 100 parts by weight of the polyolefin resin.

The di-substituted benzylidenesorbitol composition-can be blended intothe polyolefin resin having a crystallinity of 70% or more and amolecular weight distribution of 2 to 15, preferably a crystallinity of80% or more and a molecular weight distribution of 2.5 to 12 whichexhibits a great blending effect by an arbitrary known blending means,and the blend prepared in a high concentration can be used as amasterbatch resin.

In the di-substituted benzylidenesorbitol composition, it is importantthat the surface of the solid particles of the dibenzylidenesorbitolderivative is coated with at least one of the higher fatty acid, and/orthe higher fatty acid compound and/or the plasticizer and theaforementioned effects cannot be obtained by mere blending of thedibenzylidene sorbitol derivative and the higher fatty acid.

Moreover, in order to obtain the aforementioned effects, a heat historyof no less than 180° C., preferably not less than 190° C., particularlypreferably not less than 200° C. is necessary. The heat history issufficient by once. For example, the polyolefin resin composition isblended with 0.01 to 2 wt. % of the above di-substitutedbenzylidenesorbitol composition, and pelletized with heating than 190°C. particularly preferably not less than 200° C. The pellets are usedfor molding a light-shielding polyolefin resin film or the like. Evenwhen the molding resin temperature is less than 180° C., theaforementioned effects are obtained. However, by rendering the moldingresin temperature also not less than 180° C. i.e. twice heat history ofnot less than 180° C.), the molded thermoplastic resin film is veryexcellent in physical properties and rigidity, and has high surfacegloss and rare occurrence of appearance troubles, such as wrinkling andstreaks. In the case of injection-molded articles, similarly, theinjection-molded article is excellent in physical strength, rigidity,wear resistance, gloss, hardness, dimensional stability, injectionmoldability, etc. When no coloring material is blended, theinjection-molded article is excellent in transparency.

In order to exhibit the blending effects of the nucleating agent,preferable thermoplastic resins to which the nucleating agent is blendedare polypropylene resins and polyethylene resins having a molecularweight distribution (weight average molecular weight/number averagemolecular weight) of 1.5 to 12, preferably 2 to 10, particularlypreferably 2.5 to 8.

The di-substituted benzylidenesorbitol composition exhibits variousadvantages compared with conventional organic nucleating agent, such asnot degrading various properties,such as physical strength, bleeding outand rigidity, but occasionally improving the above properties, beingexcellent in odorless propertiy, resistance to appearance troubles, suchas wrinkling and streaks, the improvement in film moldability, filmforming speed, and in the case of injection-molded articles, thedecrease of molding troubles such as gate remainders, by blending thepolyolefin resin composition. That is, packaging materials for aphotographic photosensitive material excellent in physical strength,rigidity, rare bleeding out, odorless property, film moldabilityinjection moldability, dimensional accuracy, and wear resistance etc.can be provided by blending the polyolefin resin composition of theinvention with the di-substituted benzylidenesorbitol composition.

Although the reason why the di-substituted benzylidenesorbitolcomposition exhibits the above excellent effects is not clear, it can beconsidered that benzaldehyde, which is a raw material of conventionaldibenzylidenesorbitol, and benzaldehyde derivatives such a p-substitutedbenzaldehyde which are raw materials of the dibenzylidene sorbitolderivative of the invention, have odor, and a trace amount thereofunavoidably-remains in dibenzylidenesorbitol or its derivative afterpurification to cause foreign odor of clear or light-shieldingpolyolefin resin, and that a small amount of dibenzylidenesorbitol orits derivative is decomposed during molding the clear or light-shieldinginjection-molded article or the clear or light-shielding thermoplasticresin film to cause foreign odor.

By satisfying the requirement of using the solid particles of thedibenzylidenesorbitol derivative of the aforementioned formula andcoating them with the higher fatty acid of the aforementioned formula,the disubstituted benzylidenesorbitol composition exhibits the effect ofsharply decreasing the foreign odor of the injection-moldedthermoplastic resin articles and the thermoplastic resin film, etc. ofthe invention and the effect of improving the aforementioned variousproperties, such as rigidity, hardness, dimensional accuracy, wearresistance and physical strength.

Various organic nucleating agent may be used as a single material orcombined with inorganic nucleating agent or with one or more otherorganic nucleating agent. The surface of organic and/or inorganicnucleating agent may be coated with various lubricant, such as fattyacid, fatty acid compound or silicone, coupling agent, plasticizer,dispersing agent such as surfactant, wetting agent or the like.

The inorganic nucleating agent usable in the invention includes clays,such as talc, clay, mica, montmorillonite and bentonite, inorganicsalts, such as calcium silicate, magnesium silicate, calcium sulfate,barium sulfate, lithium carbonate, sodium carbonate, sodium hydrogencarbonate, potassium hydrogen carbonate, calcium carbonate, magnesiumcarbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide,calcium hydroxide, magnesium hydroxide and barium hydroxide, metaloxides, such as sodium oxide, calcium oxide, magnesium oxide, alumina,titanium oxide, iron oxide and zinc oxide.

A suitable blending amount of the inorganic nucleating agent is 0.01 to5 wt. % preferably 0.03 to 3.5 wt. %, more preferably 0.06 to 2 wt. %,most preferably 0.1 to 1 wt. %. When the blending amount is less than0.01 wt. %, the improvement in rigidity, heat resistance and hardness isinsufficient. On the other hand, when the blending amount exceeds 5 wt.%, the improvement in rigidity, etc. by the excess amount is small.

Examples of the antioxidant applicable to the invention are as follows:

Phenolic Antioxidants:

6-t-butyl-3-methylphenol derivatives, 2,6-di-t-butyl-phenol,2,6-di-t-butyl-p-ethylphenol, 2,6-di-t-butyl-p-cresol (BHT),2,2'-methylenebis-(4-ethyl-6-t-butylphenol),2,2-methylenebis-(4-methyl-6-t-butylphenol),4,4'-butylidenebis(6-t-butyl-m-cresol),4,4'-thiobis(6-t-butyl-m-cresol), 4,4-dihydroxydiphenylcyclohexane,alkyl group-induced bisphenol, styrene group-induced phenol, 2,6-di-tbutyl-4-methylphenol,n-octadecyl-3-(3,5'-di-t-butyl-4'-hydroxyphenyl)propionate,2,2,'-methylenebis(4 methyl-6-t-butylphenol),4,4'-butylidenebis(3-methyl-6-t-butylphenol),stearyl-β-(3,5-di-4-butyl-4-hydroxyphenyl)propionate,1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane,1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene,tetrakis methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate!methane, etc.

Ketone-Amine Condensate Antioxidants:

6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, polymers of2,2,4-trimethyl-1,2-dihydroquinoline, trimethyldihydroquinolinederivatives, etc.

Arylamine Antioxidants:

Phenyl-α-naphthylamine, N-phenyl-β-naphthylamine,N-phenyl-N'-isopropyl-p-phenylenediamine,N,N'-diphenyl-p-phenylenediamine, N,N'-di-β-naphthyl-p-phenylenediamine,N-(3'-hydroxybutylidene)-1-naphthylamine, etc.

Imidazole Antioxidants:

2-mercaptobenzomidazole, zinc salt of

2-mercaptobenzomidazole,

2-mercaptomethylbenzoimidazole, etc.

Phosphite Antioxidants:

Alkyl--induced arylphosphite, diphenylisodecylphosphite, sociumphosphite salt of tris(nonylphenyl)phosphite, trinonylphenylphosphite,triphenylphosphite, etc.

Thiourea Antioxidants:

Thiourea derivatives, 1,3-bis (dimethylaminopropyl)-2-thiourea, etc.

Other Antioxidants:

Those useful for air oxidation, such as dilauryl thiodipropionate, metaldeactivators, etc.

Among the above antioxidants, phenolic antioxidants and phosphiteantioxidants are preferable, and for example, each antioxidants areincorporated in an amount of 0.001 to 0.5 wt. %, and as the sum of bothantioxidants becomes 0.002 to 1 wt. %, in view of no adverse affect uponphotographic properties of photographic photosensitive materials and ofno adverse affect upon moldability.

Moreover, among the phenolic antioxidants, those having a molecularweight of 350 or more are preferable because of small bleeding,resistance to the high temperature of molding, small fuming and rareadverse affects upon photographic properties of photographicphotosensitive materials, and examples are various hindered phenolicantioxidants, such as tetrakis(methylene-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate) methane,1,3,5-tris-(2-butyl-4-hydroxy-5-di-t-butyl)butane, etc.

Particularly preferable antioxidants are hindered phenolic antioxidantsbecause of rare adverse affect upon photographic properties ofphotographic photosensitive materials. The hindered phenolicantioxidants are 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl) benzene, tetrakis(methylene(3,5-di-tert-butyl-4-hydroxy-hydrocinnamate)methane),octadecyl-3,5-di-tert-butyl-4-hydroxy-hydrocinnamate, 2,2',2'-tris(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxy ethylisocyanulate,1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-di-methylbenzyl) isocyanulate,tetrakis (2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphite ester,tetrakismethylene-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate!methane,4,4'-triobis-(6-tert-butyl-o-cresol),2,2'-thiobis-(6-tert-butyl-4-methylphenol),tris-(2-methyl-4-hydroxy-5-tert-butylphenyl)butane,2,2'-methylene-bis-(4-methyl-6-tert-butylphenol),4,4'-methylene-bis-(2,6-di-tert-butylphenol),4,4'-butylidenebis-(3-methyl-6-tert-butylphenol),2,6-di-tert-butyl-4-methylphenol,4-hydroxymethyl-2,6-di-tert-butylphenol, 2,6-di-tert-4-n-butylphenol,2,6-bis(2'-hydroxy-3'-tert-butyl-5'-methylbenzyl)-4-methylphenol,4,4'-methylene-bis-(6-tert-butyl-o-cresol),4,4'-butylidene-bis-(6-tert-butyl-m-cresol, 3·9-bis{1·1-dimethyl-2-(β-(3-t-butyl-4-hydrox-5-methylphenyl)propionyloxy)ethyl} 2,4·8,10-tetraoxospiro 5,5!undecane, and the like.Preferable antioxidants have a melting point of 100° C. or more,particularly preferably 120° C. or more, in view of small bleeding out,small thermal decomposition, and small adverse affect upon photographicphotosensitive materials. Moreover, it is effective to combine aphosphorous-containing antioxidant with the hindered phenolicantioxidant. To combine a phosphorous-containing antioxidant and ahydrotalcite compound with the hindered phenolic antioxidant isparticularly preferable for packaging materials for a photographicphotosensitive material, because of obtaining excellent photographicproperties, of no rusting a molding machine, and of preventing thedecrease of physical strength caused by thermal degradation ofthermoplastic resin and the generation of coloring troables and lumps(agglomerates of foreign material) caused by resin yellowing.

Preferable antioxidants are phenolic antioxidants, and particularlyeffective antioxidants are BHT, low volatile high molecular weightpenolic antioxidants ("Irganox 1010", "Irganox 1076", trade names ofCiba-Geigy A.G., "Ionox 330", trade name of Shell, "Good-Rite 3114"trade name of Goodrich, "Topanol CA", trade name of I.C.I., etc.),dilaurylthiodipropionate, distearylthiodipropionate, dialkylphosphate,etc. Two or more antioxidants may be combined.

Furthermore, oxidation inhibition is synergistically exercised bycombining carbon black or the like, and particularly exercised bycombining a phenolic antioxidant, a phosphorus-containing antioxidantand carbon black.

Besides, other antioxidants usable in the invention can be selected fromthose disclosed in "Plastic Data Handbook" (published by Kyogyo ChosaKai), pages 794-799, "Plastic Additives Data Collection" (published byThe Chemical Dail Co., Ltd.), pages 327-329, "Plastic Age Encyclopedia,Advance Editions 1986" (published by Plastic Age), pages 211-212, etc.

As the combination of two or more antioxidants, there are those selectedfrom combinations of an alkyl substituted monophenol antioxidant and/oran alkyl substituted polyphenol antioxidant and/or an organic phosphitecompound antioxidant and/or an organic phosphite ester antioxidant, suchas combinations of a hindered phenolic antioxidant and a pentaerythritolphosphite compound antioxidant, combinations of a hindered phenolicantioxidant and a diorganic pentaerythritol diphosphite compoundantioxidant, combinations of a hindered phenolic antioxidant and aphosphite ester antioxidant, etc.

A suitable blending amount of antioxidant is 0.001 to 5 wt. %,preferably 0.005 to 3 wt. %, more preferably 0.01 to 1.5 wt. %, mostpreferably 0.02 to 1 wt. %. When the content is less than 0.001 wt. %,the prevention of thermal degradation and coloring of resin isinsufficient. As a result, decomposition or crosslinking occurs duringmolding at a high temperature resulting in the variation of resinfluidity and in the generation of aldehydes and lumps which adverselyaffect photographic properties. When the content exceeds 5 wt. %, theantioxidants adversely photographic properties of photographicphotosensitive materials even in the case of phenolic antioxidant (it isnecessary to select antioxidants strictly.)

The color masterbatch resin composition for a packaging material for aphotographic photosensitive material may contain at least one of aradical scavenger, the aforementioned fatty acid metal salt (metallicsoap), a hydrous double salt compound and an antioxidant synergist, inorder to enhance the prevention of thermal degradation of resin, inaddition to the antioxidant. By incorporating at least one of radicalscavenger, the fatty acid metal salt, hydrous double salt compound andantioxidant sypergist, thermal degradation and thermal decomposition ofresins and low molecular weight additives are inhibited, and remarkablevariation of resin fluidity and generation of lumps can be prevented.Furthermore, generation of thermal decomposition products (aldhydes,etc.) which adversely affect photographic photosensitive materials isprevented, and catalyst residues are rendered harmless byneutralization.

A suitable content of each of the above additives is 0.001 to 10 wt. %.,preferably 0.005 to 5 wt. %, more preferably 0.01 to 3 wt. %. Takingcost, photographic properties, appearance, etc. into consideration, themost preferable content is 0.05 to 1.5 wt. %. When the content is lessthan 0.001 wt. %, the blending effect is insufficient. When the contentexceeds 10 wt. %, various troubles occur, such as generation of lumps,appearance degradation, decrease of physical strength, degradation ofphotographic properties (occurrence of fogging, spot trouble, abnormalsensitivity, etc.) produce a great quantity of alcohols, aldehydes,acids and the like, and they react with each other to produce polymer.In order to prevent oxidation of hydrocarbon, it is necessary tointercept the above chain reaction, and antioxidant is used for thatpurpose. Besides, it is also preferable to add the following radicalscavenger.

As the radical scavenger suitable for the invention, there are1,1-diphenyl-2-picrylhydrazyl, 1·3·5-triphenyl-ferudazyl,2·2,6·6-tetramethyl-4-piperidone-1-oxyl, N-(3-N-oxyanilino-13-dimethylbytylidene) anilinoxide, high valency metal salts, such asferric chloride, diphenylpicrylhydrazine, diphenyamine, hydroquinone,t-butylcatechol, dithiobenzyldisulfide, p'-ditolyltrisulfide,benzoquinone derivatives, nitro compounds, nitroso compounds, and thelike. Among them, to use hydroquinone is particularly preferred. Theabove radical scavenger may be used as a single material, or severalkinds may be combined.

It is preferable to blend the hydrous double salt compound because ofexhibiting similar effect to deterioration preventing agent, such asantioxidant.

Preferable hydrous double salt compounds for the invention includehydrotalite compounds having a general formula of

    M.sub.x R.sub.y (OH).sub.2x+3y-2z (A).sub.z ·aH.sub.2 O

In the formula, M represents Mg, Ca or Zn, R represents Al, Cr of Fe, Arepresents CO₃ or HPO₄, and x, y, z and a are positive numbers,respectively.

, and examples are Mg₆ Al₂ (OH)₁₆ CO₃ ·4H₂ O, Mg₈ Al₂ (OH)₂₀ CO₃ ·5H₂ O,Mg₅ Al₂ (OH)₁₄ CO₃ ·Mg₁₀ Al₂ (OH)₂₂ (CO₃)₂, ·4H₂ O, Mg₆ Al₂ (OH)₁₆ HPO₄·4H₂ O, Ca₆ Al₂ (OH)₁₆ CO₃ ·4H₂ O, Zn₆ Al₂ (OH),₆ CO₃ ·4H₂ O, Mg₄.5 Al₂(OH)₁₃ CO₃ ·3.5H₂ O, etc.

Other preferable hydrous double salt compounds include hydrotalcitecompounds having a refractive index of 1.40 to 1.60, preferably 1.45 to1.55, and having a general formula of

    M.sub.(1-x) ·Al.sub.x ·(OH).sub.2 ·X.sub.x/n ·mH.sub.2 O

In the formula, M represents an alkaline earth metal or Zn, X representsn valent anion, and x and m satisfy o<x<0.5 and O

, wherein examples of the n valent anion are Cl⁻, Br⁻, I⁻, NO₃ ⁻, ClO₄⁻, SO₄ ²⁻, CO₃ ²⁻, SiO₃ ²⁻, HPO₄ ²⁻, HBO₃ ²⁻, PO₄ ²⁻, Fe(CN)₆ ³⁻,Fe(CN)₄ ⁴⁻, CH₃ COC⁻, C₆ H₄ (OH)COO⁻, ##STR6##

Sill otter preferable hydrous double salt compounds include hydrotalcitecompounds composed of magnesium and aluminum having a general formula of

    Mg.sub.1-x Al.sub.x (OH).sub.2 A.sub.x/2 ·mH.sub.2 O

In the formula, x is a real number in the range of o<x≦7, A representsCO₃ and, and m is a real number. The inventor founded that thehydrotalcite compounds not only exhibit almost the same effects asantioxidant but also function to remove adverse affects uponphotographic properties of photographic photosensitive materials byneutralizing catalyst residues, Examples are

Mg₀.7 Al₀.3 (OH)₂ (CO₃)₀.15 ·0.54H₂ O

Mg₀.67 Al₀.33 (OH)₂ (CO₃)₀.165 ·0.5H₂ O

Mg₀.67 Al₀.33 (OH)₂ (CO₃)₀.165 ·0.2H₂ O

Mg₀.6 Al₀.4 (OH)₂ (CO₃)₀.2 ·0.42H₂ O

Mg₀.75 Al₀.25 (OH)₂ (CO₃)₀.125 ·0.63H₂ O

Mg₀.83 Al₀.17 (OH)₂ (CO₃)₀.85 ·0.4H₂ O

The hydrous double salt compound may be natural or synthetic. Thesynthetic methods disclosed in Japanese Patent KOKOKU 46-2280 and50-30039 can be used therefor. Particularly preferred are hydrotalcitecompounds of which crystal structure and crystal size are not limited.As natural hydrotalcite compounds, there are hydrotalcite, stichtite,pyroaurite, etc. The hydrous double salt compound may be use as a singlematerial or combined two or more. Particularly, it is preferable to usetogether with the antioxidant or the fatty acid metal salt.

A suitable blending amount of the hydrous double salt in the resincomposition is 0.001 to 5 wt. %, preferably 0.005 to 3.5 wt. %, morepreferably 0.01 to 2 wt. %, most preferably 0.05 to 1 wt. %. When theblending amount is less than 0.001 wt. %, the blending effect isinsufficient, and coloring or resin degradation of molded articlesoccur. When the blending amount exceeds 5 wt., %, appearance of moldedarticles is degraded by generation of lumps and degradation of gloss.The particle size if the hydrotalcite compound is not limited, but inview of processibility, such as injection moldability, properties, etc.,a suitable mean secondary particle size is 20 μm or less, preferably 10μm or less, particularly preferably 5 μm or less, and as to BET specificsurface area, suitably 50 m² /g or less, preferably 40 m² /g or less,particularly preferably 30 m² /g or less.

It is preferable to treat the hydrotalcite compound by a surfacetreating agent. By treating with surface treating agent, dispersibilityand miscibility against resin are further improved, and processibilitysuch as injection moldability, properties, and the like are alsoimproved.

As examples of the surface treating agent, there are higher fatty acidmetal salts, such as sodium laurate, potassium laurate, sodium oleate,potassium oleate, calcium oleate, magnesium stearate, sodium stearate,potassium stearate, sodium palmitate, potassium palmitate, sodiumcaprate, potassium caprate, sodium myristate, potassium myristate,sodium linolate and potassium linolate, higher fatty acids, such aslauric acid, palmitic acid, oleic acid, stearic acid, capric acid,myristic acid and linolic acid, organic sulfonic acid metal salts, suchas calcium dodecylbenzene sulfonate and sodium dodecylbenzene sulfonate,coupling agents, such as isopropyltriisostearoyl titanate,isopropyltris(dioctylpyrophosphate) titanate,tetraisopropylbis(dioctylphosphite) titanate, vinyltriethoxysilane,gamma-methacryloxypropyltrimethoxysilane andgamma-glycidoxypropyltrimethoxysilane, and various lubricants, such ashigher fatty acid amides, higher fatty acid esters, silicones and waxes.

The surface treatment using the surface treating agent can be conducted,for example, by adding an aqueous solution of a higher fatty acid alkalimetal salt to the hydrotalcite compound suspended in hot water withstirring, or by adding a melted higher acid or a coupling agent solutiondropwise to a hydrotalcite compound stirred by a Henschel mixer. Asuitable amount of the surface treating agent is, in general, 0.01 to 50wt. %, preferably 0.05 to 35 wt. %, more preferably 0.1 to 20 wt. %,most preferably 0.5 to 10 wt. %. Moreover, a small amount of impurities,such as other metal oxides, may contain so far as not degrading theeffects of the invention.

Moreover, in order to improve dispersibility of the hydrotalcitecompound, one or more of a higher fatty acid, a fatty acid amidelubricant, a silicone oil, a sorbitan fatty acid ester, such as sorbitanmonostearate, and a glycerine fatty acid esters, such as glycerinemonostearate may be added the resin composition as dispersing agent inan amount as the total of 0.01 to 10 wt. %, preferably 0.05 to 8 wt. %,more preferably 0.08 to 5 wt. %, most preferably 0.1 to 3 wt. %. Bycombining with the hydrous double salt compound, processibility andanticorrosion are improved, coloring and resin degradation of moldedarticles are prevented, transparency is improved, decrease of physicalstrength is prevented, and lump generation caused by resin yellowing isprevented. It is particularly preferable to combine one or morestabilizers selected from the group consisting of phenolic antioxidants,phosphorous-containing (phosphite) antioxidants and fatty acid metalsalts which synergistically improve the above functions.

In this case, in order not to affect adversely photographic performanceof photographic photosensitive materials,

1 to blend 0.0005 to 0.5 wt. %, preferably 0.001 to 0.4 wt. %,particularly preferably 0.002 to 0.3 wt. %, of a phenolic antioxidant,

2 to blend 0.0005 to 0.5 wt. %, preferably 0.001 to 0.4 wt. %,particularly preferably 0.002 to 0.1 wt. %, of a phosphorus-containingantioxidant,

3 to blend 0.0005 to 10 wt. %, preferably 0.001 to 5 wt. %, particularlypreferably 0.002 to 3 wt. %, of a hydrous double salt compound and/or afatty acid metal salt (metallic soap),

and the total blending amount of 1+2+3becomes 0.0015 to 11 wt. %,preferably 0.002 to 10 wt. %, more preferably 0.003 to 9 wt. %, mostpreferably 0.005 to 8 wt. % of the packaging material for a photographicphotosensitive material. In any event, it is preferable to blend aminimum amount capable of preventing resin degradation in view of notdegrading photographic performance and inhibriting increase of cost.

By combining the antioxidant synergist with one or more of theaforementioned antioxidant, radical scavenger, hydrous double saltcompound, thermal degradation or thermal decomposition of resins and lowmolecular weight additives (lubricant, antistatic agent, organicnucleating agent, dripproofing agent, compatibilizing agent, etc.),degradation of physical strength, remarkable variation of resin fluidityand generation of lumps can be prevented. Furthermore, generation ofthermal decomposition products (aldehydes, etc.) which adversely affectphotographic photosensitive material can be prevented. As theantioxidant synergist, there are phosphoric acid, citric acid,phosphoric acid compounds, citric acid compounds, etc. Particularly,phosphoric acid metal salts, and citric acid metal salts are preferable.

It is also preferable to add an ultraviolet stabilizer which preventsthe degradation of thermoplastic resin, such as various polyolefinresins, homopolystyrene resins and the rubber-containing aromatic vinylresin, similar to the antioxidant, the radical scavenger, theantioxidant synergist and the age resistor. Representative ultravioletstabilizer are salicylate ultraviolet stabilizers, such asphenylsalicylate, p-t-butylphenylsalicylate and p-octylphenylicylate,benzophenone ultraviolet stabilizers, such as 2,4-dihydroxybenzophenone,2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone,2-hydroxy-4-dodecyloxybenzophenone,2,2'-dihydroxy-4-methoxybenzophenone,2,2'-dihydoxy-4,4'-dimethoxybenzophenone and2-hydroxy-4-methoxy-5-sulfobenzophenone, benzotriazole ultravioletstabilizers, such as 2-(2'-hydroxy-5'-methylphenyl)benzotriazole,2-(2'-hydroxy-5'-t-butylphenyl) benzotriazole,2-(2'-hydroxy-5'-di-t-butylphenyl)benzotriazole,2-(2'-hydroxy-3',5'-di-t-butylphenyl'benzotriazole,2-(2'-hydroxy-3'-t-butyl-5'-methylphenyl)-5-chlorobenzotriazole,2-(2'-hydroxy-3',5'-di-t-butylphenyl)-5-chlorobenzotriazole,2-(2'-hydroxy-3',5'-di-t-amylphenyl)benzotriazole,2-(2'-hydroxy-4'-octoxyphenyl)benzotriazole,2-(2'-hydroxy-3'-(3",4",5",6"-tetrahydrophthalimidemethyl)-5'-methylphenyl)-benzotriazoleand2,2-methylene-bis(4-(1,1,3,3-tetramethylbutyl)-6-(2H-benzotriazole-2-il)phenol),and cyanoacrylate ultravioletstabilizers, such as2-ethylhexyl-2-cyano-3,3'-di-phenylacrylate andethyl-2-cyano-3,3'-diphenylate, and the like. A suitable blending amountis 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight,particularly preferably 0.1 to 3 parts by weight, per 100 parts byweight of thermoplastic resin, such as various polyolefin resins,homopolystyrene resin, polyamide resin or rubber-containing aromaticvinyl resin. The blending amount of less than 0.01 part by weightresults in insufficient effects on ultraviolet stabilization, and on theother hand, the blending amount of more than 10 parts by weight resultsin the occurrence of bleeding out which adversely affects photographicproperties of photographic photosensitive materials. Two or moreultraviolet stabilizers may be combined.

In the invention, it is preferable to add an age resistor which preventsthe degradation of thermoplastic resin, such as various polyolefinresins, homopolystyrene resin or the rubber-containing aromatic vinylresin, similar to the antioxidant and the radical scavenger.Representative age resistors are naphthylamines such asphenyl-β-naphthylamine, diphenylamines such asN,N'-diphenylethylenediamine, p-phenylenediamines such asN,N'-diphenyl-p-phenylenediamine, hydroquinone derivatives such as6-ethoxy-2,2,4-trimethyl-1,2-dihydroquinoline, monophenols such as2,6-di-tert-butyl-4-methylphenol, polyphenols such as 2,2'-methylene-bis(4-ethyl-6-t-butylphenol, thiobisphenols such as4,4'-thiobis-(6-t-butyl-3-methylphenol), 2-mercaptobenzoimidazole andthe like. They are optionally blended according to theircharacteristics. A suitable blending amount is 0.01 to 10 parts byweight, preferably 0.05 to 5 parts by weight, particularly preferably0.1 to 3 parts by weight, per 100 parts by weight of thermoplasticresin, such as various polyolefin resins or rubber-containing aromaticvinyl resin. The blending amount of less than 0.01 part by weightresults in insufficient blending effects on the prevention of aging, andon the other hand, the blending amount of more than 10 parts by weightresults in the occurrence of vulcanization troubles and remarkableblooming.

Various additives may be added to the color masterbatch resincomposition for a packaging material of the invention. Various additivesare described in "Saishin Ganryo Binran (The Newest Pigment Handbook),Revised and Enlarged Edition" published by Seibundo Shinko Sha on Jan.10, 1977, "Shin Kagaku (New Chemical) Indenx" published by The ChemicalDaily Co., Ltd. on Jul. 23, 1993, "12394 no Kagaku Shohin (12394Chemical Goods)" published by The Chemical Daily Co., Ltd. on Jan. 26,1994, "Plastic Data Handbook" published by Kogyo Chosa Kai on Apr. 5,1984, "Jitsuyo Plastic Yogo Jiten (Practical Plastic Term Dictionary),Third Edition" published by Plastic Age, in detail. Most of theadditives are applicable to packaging materials for photographicphotosensitive materials by selecting the type of additive, by limitingblending amount, or by utilizing a reaction rendering harmless bycombining other additive(s), or by investigating layer construction orresin composition.

Representative examples are-described below.

A. First Classification (classification by performance against need)

1. Processing Assistant

a. Processing Stabilizer (antioxidant, heat stabilizer) (PVC stabilizer)

b. Fluidity Controller (plasticizer, lubricant)

c. Shape Retention Assistant (mold releasing agent, contractionpreventing agent)

2. Modifier

2-1. Stabilizer (Life Controller)

a. Antioxidant

b. Light Stabilizer

c. Flame Retardant

d. Biostabilizer

e. Metal Deactivator

f. Deterioration Restoring Agent

2-2. Performance Modifier (Property Controller)

a. Impact Resistance Improver (various elastomers, L-LDPE resin)

b. Filler, Reinforcing Agent

c. Colorant

d. Plasticizer

e. Foaming Agent

f. Crosslinking Agent (organic peroxides)

g. Nucleating Agent

2-3. Function Modifier (Function Imparting Agent)

a. Conductive Agent. Magnetic Agent

b. Antistatic Agent

c. Fluorescent Whitening Agent

2-4. Decomposition Accelerator

a. Biodegradation

b. Photodegradation

c. Thermal Degradation, etc.

B. Second Classification (classification by attribute of additives)

1. Power Modifier

a. Reinforcing Agent/Filler

b. Nucleating Agent

c. Processing Assistant

d. Powder/Special Structure Powder

2. Reactivity Modifier

a. Crosslinking Agent

b. Macromonomer

c. Stabilizer (heat, light, radioactive ray, bio)

d. Decomposition Accelerator (bio, light, heat)

3. Interface Modifier

a. Coupling Agent

b. Compatibilizing Agent

c. Plasticizer/Solvent

4. Polymer Modifier

a. Processibility Improve, Performance Modifier

b. Alloy, Blend (performance modifier), etc.

The color masterbatch resin composition for a packaging material havingthe foregoing resin composition can be prepared a conventional method. Awater content of the resin composition is preferably as small aspossible, because water causes unexpected troubles, such as silverstreaks, foaming and short shot. Therefore, an oven-dry water content isusually made 0.8 wt. % or less, preferably 0.5 wt. % or less, morepreferably 0.4 wt. % or less, most preferably 0.3 wt. % or less.

Particularly, carbon black, which is a light-shielding material mostfrequently used for packaging materials for a photographicphotosensitive material, is liable to absorb water. Accordingly, when acarbon black content of color masterbatch resin composition pellets isincreased, moisture absorption increases with time. Then, in the case ofstoring the pellets for a long period, unless they are packaged by amoistureproof packaging bag, the moisture content gradually increases.

Carbon black masterbatch resin pellets composed of LDPE resin and 20 wt.% or 40 wt. % carbon black were prepared, and stored for four months ina kraft paper bag formed of four layers of which the innermost layer was50 μm polyethylene. Moisture absorption degree was measured at everymonth and the results are shown in the following table.

    ______________________________________                                                    Moisture Content (wt. %)                                          Time (month)  0       1       2    3     4                                    ______________________________________                                        20 wt. % Carbon Black                                                                       0.06    0.2     0.3  0.35  0.45                                 40 wt. % Carbon Black                                                                       0.15    0.35    0.5  0.6   0.75                                 ______________________________________                                    

Subsequently, the carbon black masterbatch resin pellets which hadabsorbed moisture were attempted to remove the absorbed moisture byheating at 80° C., and the variation of moisture content was measured.The results are shown in the following table.

    ______________________________________                                                    Moisture Content (wt. %)                                          Time (hour)   0       1       2    3     4                                    ______________________________________                                        20 wt. % Carbon Black                                                                       1.2     0.9     0.75 0.6   0.45                                 40 wt. % Carbon Black                                                                       0.6     0.4     0.3  0.2   0.17                                 ______________________________________                                    

As shown in the above table, it is very difficult to remove moisturefrom carbon black masterbatch resin composition pellets once absorbedmoisture only by heating. In the above tables, the moisture content isan oven-day water content.

Accordingly, it is preferable to dry the color masterbatch resincomposition by using a vacuum hopper in a combination of heating andreducing pressure lower than atmospheric pressure. When reducingpressure to 80 mm Hg or less is combined with heating, drying time canbe shortened to 1/3 or less compared with drying only by heating. Thismethod is particularly preferable for drying a color masterbatch resincomposition containing 40 wt. % or more carbon black.

The color masterbatch resin composition for a packaging material of theinvention is kneaded and melted with a thermoplastic resin for dilution,and molded into various packaging materials for a photographicphotosensitive material.

As the thermoplastic resin for dilution, various aforementionedthermoplastic resins are usable. Particularly, preferable thermoplasticresins for photographic photosensitive materials include LDPE resins,MDPE resins, HDPE resins, L-LDPE resins, EEA resins, EVA resins, EAAresins, homopolypropylene resins, propylene-ethylene block copolymerresins, propylene-ethylene random copolymer resins, polyamide resins,polyester resins, polystyrene resins, rubber-modified polystyrene resins(high-impact polystyrene resins), ABS resins, polyacetal resins,polycarbonate resins, vinyl chlovide resins, EVOH resins, etc.

A method of weighing and mixing pellets of the color masterbatch resincomposition with pellets of a thermoplastic resin for dilutionautomatically is as follows:

Pellets of the color masterbatch resin composition and pellets of athermoplastic resin for dilution are weighed by two turntables. Theturntable weighing the pellets of a thermoplastic resin for dilutioncontinuously turns at a constant speed, and the flow rate of the pelletsis controlled by opening and closing by the vertical movement of adamper similar to a water gate attached under a hopper. The flow rate ofthe pellets of the color masterbatch resin composition can be controlledby two means. One is a damper similar to the damper used for the pelletsof a thermoplastic resin for dilution, and the other is by adjusting arotation angle of the turntable. That is, not the turntable turnscontinuously but the interval of stroke can very be the intermittentmotion of a cam mechanism. As a result, on a continuous flow of thepellets of a thermoplastic resin for dilution, the pellets of the colormasterbatch resin composition drop intermittently. Since uneven mixingoccurs caused by the specific gravity difference between two components,static electrification, and the difference of pellet size whichaccelerate their separation attention is required. On the other hand,the separation also occurs during pneumatic transportation afterblending and in a hopper of a molding machine. Accordingly, it ispreferable to mount an automatic weighing machine on the hopper, and tocontrol the weighing by a level meter so that a stocked amount in thehopper is kept small. Moreover, it is preferable to employ a weightmeasuring system.

A line mixer without any movable part is illustrated in FIG. 20. Theline mixer is called "Thermogenizer" and made by applying the principleof a pipe mixer "Static Mixer" (Japanese Patent 553918) to extrusionmolding. By providing the line mixer between an extruder and a die,temperature gradient of a molten thermoplastic resin flowing from theextruder to the die is dissolved, and the dispersion of alight-shielding material into a thermoplastic resin is uniformed.

The element of the Static Mixer are inserted into the barrel of theThermonizer, and fixed. The element is formed of connecting a pluralityof twist rectangular or square plates in series by welding so that eachconnecting side is arranged so as to cross at a right angle. Respectivetwist rectangular or square plates are formed by twisting both sides at180 degrees in the direction opposite to each other. A moltenthermoplastic resin is divided exponentially into 1/2, 1/4, 1/8, 1/16 .. . by passing every twist plate portion. Moreover, since every plate istwisted, the molten thermoplastic resin rotates in a radial directioncrosswisely, and a radial mixing occurs. Thereby, uneven distribution oftemperature, color and properties in the molten thermoplastic resin isdissolved at once.

Representative examples of the packaging material for a photographicphotosensitive materials of the invention are as follows:

I. Film Molded Articles:

Single layer film: Japanese Patent KOKOKU No. 2-2700, etc.

FIG. 1

Coextruded multilayer films (FIGS. 2-6).

Laminated films using a single layer film or a coextruded multilayerfilm: Japanese Patent KOKOKU Nos. 63-26697, 2-2701, 2-13774, 2-19225,etc. (FIGS. 7-9)

Packaging materials using the above flexible sheet of the single layerfilm, coextruded multilayer film or laminated film; packaging bags(unipack bag, single sheet flat bag, double sheet flat bag, single sheetgusset bag, double sheet gusset bag, etc.), shrink packaging, bulkpackaging (Japanese Patent KOKAI No. 3-53243, Japanese Utility ModelKOKAI No. 3-71346, etc.), assembly packaging, and the like and packagefor lightroom loading of a band form photosensitive material JapaneseUtility Model KOKAI Nos. 55-113543, 60-13386, 60-167796, 2-72347,3-47547, 3-54937, 3-86358, 3-96648, etc.

II. Vacuum-molded articles:

III. Injection-molded articles: spools for a photographic film, filmunits with a lens, containers for a photographic film cartridge,light-shielding containers, cartridges for a photographic film made ofplastic, light-shielding magazines for light room loading, cores,photographic film cartridges, packs for an instant film, etc.

Cartridge for disc film: Japanese Utility Model KOKAI No. 60-21743, etc.

Film unit with lens: Japanese Patent KOKAI No. 63-226643 (FIG. 16)

Spool for photographic film: Japanese patent KOKAI Nos. 1-251030,57-196218, 59-15049, 58-203436, 58-82237, 58-82236, 62-240957, JapaneseUtility Model KOKAI Nos. 63-73742, 54-120931, 58-178139-178145,63-73742, Japanese Utility Model KOKOKU Nos. 55-31541, 44-16777, U.S.Pat. No. 1,930,144, GB 2199805A (FIG. 13)

Cartridge for photographic film: Japanese Patent KOKAI Nos. 54-111822,50-33831, 56-87039, 1-312538, 57-190948, Japanese Patent KOKOKU Nos.45-6991, 55-21089, Japanese Utility Model KOKAI No. 55-97738, U.S. Pat.No. 4,846,418, U.S. Pat. No. 4,848,693, U.S. Pat. No. 4,887,776, etc.(FIG. 14)

Container for photographic film cartridge: Japanese Patent KOKAI Nos.61-250639, 61-73947, 63-121047, 62-291639, Japanese Utility Model KOKAINos. 60-163451, 1-88940, 1-113235, 1-152337, Japanese Utility ModelKOKOKU Nos. 2-33236, 3-48581, Japanese Patent KOKOKU No. 2-38939, U.S.Pat. No. 4,801,011, U.S. Pat. No. 4,979,351, EP 02370562A2, EP0280065A1, EP 0298375A2, etc. (FIGS. 10-12)

Core, Reel: Japanese Utility Model KOKAI No. 60-107848, U.S. Pat. No.4,809,923, GB 2,033,873 B, etc.

Magazine for sheet films: Japanese Utility Model KOKAI No. 56-5141, etc.

Photographic film cartridge: Japanese Patent KOKAI No. 1-312537,Japanese Utility Model KOKAI Nos. 2-24846, 2-29041, 60-120448, JapaneseUtility Model KOKOKU No. 56-16610, etc. (FIG. 18)

Photographic film case: Japanese Utility Model KOKAI No. 54-100617,64-32343, 1-94258, 2-56139, Japanese Patent KOKOKU No. 2-54934, U.S.Pat. No. 4,779,756, EP 0242905A1, etc. (FIG. 17)

The method of forming the packaging material for a photographicphotosensitive material may be selected from inflation film molding,extrusion laminating, injection molding, vacuum molding, sheet forming,T die flat film molding, pressure forming, rotational molding, intermoldvacuum injection molding and the like, according to the form of eacharticle to be molded.

In the case that the packaging material for a photographicphotosensitive material is a container for a photographic filmcartridge, ethylene-α-olefin copolymer resins, homopolyethylene resins,homopolypropylene resins, propylene-α-olefin copolymer resins,homopolystyrene resins, rubber-containing polystyrene resins, polyesterresins, acrylonitrile resins, vinyl chloride resins, etc. are preferred.

In view of moistureproofness, injection moldability, cost, and recyclingability, preferred polyethylene resins (homopolymers, random or blockcopolymers, and blends of one or more of them and one or morepolypropylene resins) have a melt flow rate (ASTM D-1238, E condition)of 5 to 80 g/10 minutes preferably 7 to 70 g/10 minutes, more preferably10 to 60 g/10 minutes, most preferably 15 to 50 g/10 minutes, a density(ASTM D-1505) of 0.935 g/cm³ or more, preferably 0.940 to 0.985 g/cm³,more preferably 0.950 g/cm³ or more, a bending rigidity (ASTM D-747) of5,000 kg/cm² or more, preferably 6,000 kg/cm² or more, more preferably8,000 kg/cm² or more, most preferably 10,000 kg/cm² or more.

In the case of transparent containers, suitable resin compositionscomprises 50 wt. % or more, preferably 65 wt. % or more, more preferably80 wt. % or more, most preferably 90 wt. % or more of one or morehomopolyethylene resins and/or ethylene-α-olefin copolymer resins havinga density of 0.935 g/cm³ or more, preferably 0.945 g/cm³ or more, morepreferably 0.955 g/cm³ or more, most preferably 0. 960 g/cm³ or more and0.01 to 2 wt. % of at least one of various nucleating agents and 0.01 to10 wt. % of at least one of various lubricants. Particularly preferableresin compositions are the aforementioned ethylene-α-olefin randomcopolymer resins having a MFR of 15 to 50 g/10 minutes a density of0.945 to 0.985 g/cm³ of which α-olefin has a number of carbon atoms of 3to 10 and propylene-ethylene random copolymer resins containing 0.01 to2 wt. % of at least one of various nucleating agents. For containerscolored white, black, brown or silver, preferable resins arepropylene-ethylene block copolymer resins and homopolyethylene resinshaving a density of 0.935 g/cm³ or more, preferably 0.945 g/cm³ or more,more preferably 0.955 g/cm³ or more.

More preferable resins than the above polyethylene resins for formingcontainer bodies for a photographic film cartridge in terms of qualityand cost are various polypropylene resins (homopolymers, random or blockcopolymers, and blends of one or more of them and one or morepolyethylene resins) have a melt flow rate (ASTM D-1238, at 230° C. at atesting load of 2.16 kgf) of 10 to 80 g/10 minutes, preferably 15 to 50g/10 minutes, particularly preferably 20 to 50 g/10 minutes,particularly preferably 20 to 45 g/10 minutes, a bending elastic modulus(ASTM D790) of 4,000 kg/cm² or more, preferably 8,000 kg/cm² or more,particularly preferably 10,000 kg/cm² or more, and a notched Izod impactstrength (ASTM D-256) at 23° C. of 2.0 kg·cm/cm or more, preferably 2.5kg·cm/cm or more, particularly preferably 3.0 kg·cm/cm or more.

Containers for a photographic film with excellent qualities can beobtained by incorporating organic compounds having a number averagemolecular weight of less than 10,000 of fatty acid metal salt or fattyacid amide lubricant and organic nucleating agent and antioxidant.

Preferable embodiments of the invention are described below.

(1) A color masterbatch resin composition for a packaging materialwherein the thermoplastic resin for dilution is ethylene-α-olefincopolymer resin.

(2) A color masterbatch resin composition for a packaging materialwherein the thermoplastic resin for dilution is rubber-containingpolystyrene resin.

(3) A color masterbatch resin composition for a packaging material,which contains one or more thermoplastic resin deterioration preventingagents selected from the group consisting of antioxidant, age resistor,radical scavenger, antioxidizing synergist, hydrous compound and hydrousdouble salt compound.

(4) A method of molding a packaging material using a color masterbatchresin composition for a packaging material for a photographicphotosensitive material wherein evaporable substances which adverselyaffect photographic properties of photographic photosensitive materialshave been removed by mounting a hopper provided with a heating and/orevacuating means at an inlet port of an extruder.

(5) A color masterbatch resin composition for a packaging materialhaving a gray appearance, wherein the light-shielding material is acombination of a white pigment and a black pigment.

(6) A color masterbatch resin composition for a packaging material,wherein the light-shielding material is a combination of a spericalpigment and a flake pigment.

(7) To incorporate an antistatic agent and/or a conductive material intoone or more of pellet of a color masterbatch resin composition for apackaging material for a photographic photosensitive material, pelletsof a thermoplastic resin for dilution, recycle resin pellets and othermaterials mixed with the pellets of a color masterbatch resincomposition is preferable in order to improve mixing workability and soas not to break an uniformly mixed state by static electrification torepel each other during transportation, storing in a hopper or to adhereto the wall of a container for transportation, conveying pipes, thehopper or the like.

(8) To combine a lubricant and/or a plasticizer with an antistatic agentand/or a conductive material is particularly preferable, because it ispossible to supply to an extruder in an uniformly mixed form by adheringto each other in addition to antistatic action, and various effects areexhibited, such as improvement in melt kneadability, in dispersion oflight-shielding material, in resin fluidity, in lubricity, and in thecase of injection molded articles and flow molded articles, in moldreleasability, in shortening of molding cycle, etc.

(9) Even when uniformly mixed, the mixture is separated again duringputting into a hopper according to the form and size of pellets. Inorder to prevent the separation again and to improve uniform meltkneadability in an extruder and in economical viewpoint, preferableforms of the pellets are sphere, column, square column, square,rectangle, plate, etc., and preferable sizes are 1 to 10 mm, morepreferable 2 to 8 mm, most preferably 3 to 6 mm of a side or a diameter,and 1 to 100 mm³, more preferably 5 to 80 mm³, firtjer, preferably 10 to60 mm³, most preferably 20 to 50 mm³.

(10) Furthermore, the relation between the volume of pellets of a colormasterbatch resin composition and pellets of a thermoplastic resin fordilution is also important, and a suitable volume ratio of the pelletsof a color masterbatch resin composition to the pellets of athermoplastic resin for dilution is 0.35 to 3, preferably 0.5 to 2.3,more preferably 0.65 to 1.6, most preferably 0.8 to 1.3. An idealrelation is of having almost the same form and size between them.

(11) Preferable thermoplastic resins of a color masterbatch resincomposition are of having a higher MFR, a lower softening point and alower molecular weight than a thermoplastic resin for dilution.

(12) In the case that the light-shielding material concentration of acolor masterbatch resin composition is 20 to 80 wt. %, and that theresin composition is diluted by a thermoplastic resin for dilution in anamount of 5 to 120 times as much as that of the resin composition, it ispreferable that the size of pellets of the resin composition is slightlysmaller than pellets of the thermoplastic resin for dilution, and thatthe fluidity (MFR) of the resin composition is greater than thethermoplastic resin for dilution, because the dispersibility of thelight-shielding material is improved to prevent the generation fo unevencoloring and microgrits.

(13) As to antistatic agent, lubricant, plasticizer, light-shieldingmaterial, thermoplastic resin, etc., other materials than previouslydescribed ones, which do not affect adversely photographic properties ofphotographic photosensitive materials, are also usable. Those adverselyaffecting photographic properties are also usable by adjusting theconcentration or content to the range where adverse affects uponphotographic properties are small and no problem in practical viewpoint.It is also possible to use by making into a state of not affectingadversely photographic photosensitive materials by reacting with oradsorbing substances adversely affecting photographic properties.

(14) As preferable conductive materials for the above (7) and (8), thereare conductive carbons, such as conductive carbon blacks cacetyleneblacks, conductive furnace blacks, etc.), carbon fibers and graphites,inorganic salts, such as sodium chloride, potassium chloride, lithiumchloride, sodium alminate, sodium phosphate, calcium chloride, magnesiumchloride and sodium sulfate, organic acid salts, such as potassiumformate and sodium oxalate, surfactants, such as fatty acid metal salts(metallic soaps), phosphates and carboxylic acid salts, polymerelectrolytes, such as quaternary ammonium salts, polyacrylic acid salts,salts of styrene-maleic acid copolymer resins and polystyrenesulfonates, and inorganic conductive materials, such as silica, sluminaand montmorillonite.

(15) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, wherein the light-shieldingmaterial is an inorganic pigment or a metal powder, having a meanparticle size of 0.01 to 10 μm and a refractive index of 1.50 or moremeasured by the Larsen oil immersion, and is combined with one or moreof a lubricant, a plasticizer, a dripproofing agent and an antistaticagent or is coated with a surface-coating material.

(16) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, which is formed into pelletshaving a volume 0.35 to 3 times as much as the volume of pellets of athermoplastic resins or dilution.

(17) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, wherein the blachlight-shielding material is carbon black, the number of carbon atoms ofthe metal salt of partially saponified fatty acid ester is 20 to 50, andthe number of carbon atoms of the fatty acid and the higher fatty acidcompound is 15 to 50.

(18) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, wherein the light-shieldingmaterial is carbon black, the antioxidant is one or more of a hinderedphenol antioxidant and a phosphorous-containing antioxidant, and thelubricant is one or more of a fatty acid metal salt and a partiallysaponified fatty acid ester metal salt.

(19) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, wherein the thermoplastic resininactive to polyolefin resin has a MFR greater than the MFR of athermoplastic resin for dilution.

(20) A method of producing a color masterbatch resin composition for apackaging material, wherein the MFR of a thermoplastic resin fordilution is, in the case of a use or an inflation film, 0.1 to 7 g/10minutes, in the case of a use for a T die film, 1 to 10 g/10 minutes, inthe case of a use for an extrusion laminating, 2 to 11 g/10 minutes, andin the case of a use for an injection molded article, 2 to 50 g/10minutes.

(21) A packaging material for a photographic photosensitive materialmolded through mixing a thermoplastic resin for dilution having a MFRhigher than the MFR of a color masterbatch resin composition for apackaging material for a photographic photosensitive material in anamount three times by weight as much as or more the resin composition.

(22) A packaging material for a photographic photosensitive material,wherein a thermoplastic resin for dilution having MFR 5 times as much asor more the MFR of a color masterbatch resin composition for a packagingmaterial is mixed in an amount 5 times as much as or more the resincomposition.

(23) A packaging material for a photographic photosensitive material,wherein the thermoplastic resin for dilution is a polystyrene resin oran ABS resin and is contained in an amount three times as much as ormore the color masterbatch resin composition, the carbon black contentis 0.1 to 10 wt. %, and the lubricant content is 0.01 to 5 wt. %.

(24) A packaging material for a photographic photosensitive material,wherein the carbon black is coated with a surface-coating material.

(25) A method of producing a packaging material for a photographicphotosensitive material, wherein the pressure of the hopper and theresin feed opening is kept 80 mm Hg or less.

(26) A method of producing a packaging material for a photographicphotosensitive material, wherein the rubber-containing styrene resincomposition has a MFR of 1 to 60 g/10 minutes, a notched Izod impactstrength of 2 kg·cm/cm or more, a Vicat softening point of 80° C. ormore, a statical friction coefficient of 0.40 or less, and a bendingelectic modulus of 15000 kg/cm² or more.

(27) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, wherein the rubber-containingstyrene resin composition has a wear resistance of 10 mm³ or less.

(28) A method of producing a packaging material for photographicphotosensitive material comprising producing pellets of a colormasterbatch resin composition for packaging material for a photographicphotosensitive material by passing a resin composition comprising athermoplastic resin and a light-shielding material through a continuouskneading extruder provided with a mechanism of kneading between a rotarydisc and a fixed disc, mixing the pellets with pellets of athermoplastic resin for dilution at a predetermined ratio, and moldingthe packaging material by passing the pellet mixture through the abovecontinuous kneading extruder.

(29) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, wherein the total amount of oneor more antioxidants is 0.001 to 1 wt. %, and the total amount of one ormore of the low molecular weight polyolefin resins having a numberaverage molecular weight of 5000 or less and the compatibilizing agentsis 1 to 80 wt. %.

(30) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, wherein the lubricant is a fattyacid metal salt, the light-shielding material is a furnace carbon black,the antioxidant is a hindered phenol antioxidant, and the low molecularweight polyolefin resin is a low molecular weight polyethylene resin.

(31) A packaging material for a photographic photosensitive material,which comprises 0.001 to 0.5 wt. % of a phosphorus-containingantioxidant and 0.01 to 5 wt. % of a fatty acid metal salt (metallicsoap).

(32) A color masterbatch resin composition for a packaging material,wherein the polyolefin resin is a homoplyethylener resin and/or anethylene copolymer resin, and the light-shielding material is carbonblack.

(33) A packaging material for a photographic photosensitive material,which comprises 0.001 to 10 wt. % of a lubricant and 0.001 to 10 wt. %of one or more of a phnol antioxidant, a phosphite antioxidant, aradical scavenger, an antioxidant synergyst and a hydrous double saltcompound.

(34) A packaging material for a photographic photosensitive material,which comprises 0.01 to 10 wt. % of a fatty acid metal salt having anumber of carbon atoms of 10 to 35 and a melting point of 70° to 180° C.

(35) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, which consists essentially of 5to 80 wt. % of a light-shielding material and 20 to 95 wt. % of amixture of a styrene thermoplastic resin and an acrylic acid estercopolymer resin containing 10 wt. % or more of methyl methacrylate,wherein the ratio of styrene thermoplastic resin/acrylic acid estercopolymer resin is 20/80 to 80/20.

(36) A packaging material for a photographic photosensitive material,which comprises a blend of 100 parts by weight of a color masterbatchresin composition of claim 1 and 30 to 2000 parts by weight of arubber-containing polystyrene resin containing 0.01 to 10 wt. % of alubricant and 3 to 20 wt. % of a synthetic rubber, and contains 0.1 to 3wt. % of a light-shielding material, 0.4 to 8 wt. % of methylmethacrylate, 0.001 to 5 wt. % of a lubricant and 1 to 15 wt. % of asynthetic rubber.

(37) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, which comprises 5 to 95 wt. % ofone or more of an ethylene-α-olefin copolymer resin having a MFR of 0.1to 20 g/10 minutes, a density of 0.860 to 0.905 g/cm³, a Vicat softeningpoint of 105° C. or less and a crystallinity of 40% or less and asynthetic rubber, 0.01 to 10 wt. % of one or more of a lubricant and acoupling agent, and a light-shielding material in a content three timesas much as or more the content of the light-shielding material in thepackaging material.

(38) A packaging material for a photographic photosensitive material,which consists essentially of 100 parts by weight of the colormasterbatch resin composition of claim 1 or 2 and 500 to 12000 parts byweight of a thermoplastic resin for dilution.

(39) A color masterbatch resin composition for a packaging material fora photographic photosensitive material, which comprises 100 parts byweight of a polyolefin resin, 1 to 80 part s by weight of a polyolefinresin containing carboxyl group or acid anhydride group or an elastomer,20 to 500 parts by weight of a light-shielding material of which thesurface has been coated with a surface-coating material and 0.001 to 10parts by weight of an organic peroxide.

(40) A packaging material for a photographic photosensitive material,which is a light-shielding polyolefin resin film 30 to 300 μm inthickness composed of 100 parts by weight of the color masterbatch resincomposition of claim 1 or 2 and 300 to 2500 parts by weight of pelletsof a polyolefin resin for dilution having a MFR of 0.1 to 20 g/10minutes.

(41) The method of producing a packaging material for a photographicphotosensitive material of claim 12, 13 or 14, wherein a ring die havinga lip clearance of 0.8 to 3.5 mm used, and a film which is the packagingmaterial is molded by inflation film molding at a resin temperature of130° to 210° C.

(42) The light-shielding material in claims 1 to 15 is furnace carbonblack having a pH of 6 to 8, a mean particle size of 12 to 50 mμ and aDBP oil absorption value of 250 ml/100 g or more.

(43) The light-shielding material in claims 1 to 15 is composed of 0.1to 60 wt. % of an inorganic pigment having a mean particle size of 0.1to 20 μm and 0.1 to 60 wt. % of carbon black having a mean particle sizeof 10 to 120 mμ.

(44) The light-shielding material in claims 1 to 15 is CuO--Mn₂ O₃ --Fe₂O₃ black pigment. CuO--Cr₂ O₃ --Fe₂ O₃ black pigment or a combinationthereof.

(45) 1 wt. % or more of the thermoplastic resin in claims 1 to 15 is amodified polyolefin resin, modified by an unsaturated carboxylic acid ora derivative thereof, having a MFR of 2 g/10 minutes or more.

(46) In claims 1 to 15, 2 or more higher fatty acid metal salts arecontained.

(47) In claims 1 to 15, the thermoplastic resin used is in a form ofparticle having a volume of 1 mm³ or less.

Some packaging materials for a photographic photosensitive materialembodying the invention are illustrated in drawings.

FIGS. 1 through 9 illustrate packaging films for a photographicphotosensitive material which belong to the packaging material for aphotographic photosensitive material of the invention.

The packaging film for a photographic photosensitive material of FIG. 1is a single layer film consisting of a light-shielding thermoplasticresin film layer 1a.

The packaging film for a photographic photosensitive material of FIG. 2is a coextruded double layer film IIa consisting of a consisting of alight-shielding thermoplastic resin film layer 1a as the packagingmaterial for a photographic photosensitive material of the invention anda thermoplastic resin layer 2.

The packaging film for a photographic photosensitive material of FIG. 3is the same as the film of FIG. 2, except that the thermoplastic resinlayer 2 contains a light-shielding material.

The packaging film for a photographic photosensitive material of FIG. 4is a coextruded triple layer film IIIa consisting of a light-shieldingthermoplastic resin film layer 1a as the packaging material for aphotographic photosensitive material of the invention, an intermediatelayer 3 and a thermoplastic resin layer 2.

The packaging film for a photographic photosensitive material of FIG. 5is a laminated film IVa consisting of two coextruded double layer filmsIIa of FIG. 2 joined by blocking B between the thermoplastic resinlayers 2, 2.

The packaging film for a photographic photosensitive material of FIG. 6is a laminated film IVa consisting of two coextruded double layer filmsIIa of FIG. 3 joined by blocking B between the light-shieldingthermoplastic resin layers 2, 2.

The packaging film for a photographic photosensitive material of FIG. 7is a laminated film consisting of the above light-shieldingthermoplastic resin film layer 1a and a flexible sheet layer 5 laminatedthrough an adhesive layer 4.

The packaging film for a photographic photosensitive material of FIG. 8is a laminated film consisting of the above light-shieldingthermoplastic resin film layer 1a, a metallized biaxially stretched filmlayer 9 wherein a vacuum deposited metal layer 8 is provided on abiaxially stretched film layer 6 through an anchor coat layer 7 and aflexible sheet anchor coat layer 7 and a flexible sheet layer 5laminated each through an adhesive layer 4.

The packaging film for a photographic photosensitive material of FIG. 9is a laminated film consisting of the above light-shieldingthermoplastic resin film layer 1a a metal foil 10 and a flexible sheetlayer 5 laminated thereon each through an adhesive layer 4.

The container 14 for a photographic film cartridge of FIG. 10 consistsof a container body 15 and a cap 16. Both of the container body 15 andthe cap 16 are the packaging material of the invention.

The container for a photographic film cartridge of FIG. 11 also consistsof a container body 15 and a cap 16, and the side portion is tapered byenlarging the inside diameter (A+a) of the upper opening portion thanthe inside diameter (A) of the bottom portion by a. In order tofacilitate extracting a core upon injection molding, a suitable value ofthe a is 0.001 to 2 mm, preferably 0.01 to 1.5 mm, more preferably 0.02to 1 mm, most preferably 0.05 to 0.5 mm. The container body 15 alsobelongs to the packaging material for a photographic photosensitivematerial of the invention.

The container 14 for a photographic film cartridge of FIG. 12, which isthe packaging material of the invention, is a cap-body integrated typeconsisting of a container body 15 portion and a cap 16 portion, and isformed of the light-shielding thermoplastic resin composition of theinvention.

FIG. 13 illustrates a spool 20 for a photographic film which is thepackaging material of the invention, the whole body of the spool isformed of the light-shielding thermoplastic resin composition of theinvention.

FIG. 14 illustrates an exploded state of a photographic film cartridge17, which is the packaging material of the invention, consisting of anupper casing 18 and a lower casing 19, which constitute the cartridgebody, and a spool 20 on which the photographic film to be loaded iswound. All of the upper casing 18, the lower casing 19 and the spool 20belong to the packaging material for a photographic photosensitivematerial of the invention, and are formed of the light-shieldingthermoplastic resin composition of the invention. When taking recyclingability into consideration, it is preferable to form all of the uppercasing 18, the lower casing 19 and the spool 20 by the same or a similarresin composition.

FIG. 15 illustrates a photographic film cartridge 17 with a print havinga particular size. The cartridge body and caps are made of a metal andthe spool 20 on which the photographic film to be loaded is wound is thepackaging material for a photographic photosensitive material of theinvention and the same as disclosed in FIG. 14.

FIG. 12 illustrates an exploded state of a photographic film unit 21with a lens, which is the packaging material of the invention,consisting of a lower casing 22 in which a light-shielding photographicfilm cartridge 17 containing a photographic film wound around a spool 20is set in a state shielded from light and an upper casing 29 which sealsthe lower casing 23 so as to form a light-shielding condition. All ofthe spool 20, the lower casing 22 and the upper casing 23 are formed ofthe light-shielding polyolefin resin composition. When taking recyclingability into consideration, it is preferable to form all of thecartridge 17 for a photographic film, the spool 20, the upper casing 23and the lower casing 22 by the same or a similar resin composition.

FIG. 17 illustrates a cap-body integrated type light-shielding case 24for a photographic film, such as a microfilm, which is the packagingmaterial of the invention, consisting of a container body 15 portion anda cap 16 portion.

FIG. 18 illustrates an exploded state of a photographic film cartridge25, which is the packaging material of the invention, consisting of alower casing 26, an upper casing 27 and a spool 28 loaded therein, andall of the spool 28, the lower casing 26 and the upper casing 27 areformed of the light-shielding thermoplastic resin composition of theinvention. When taking recycling ability into consideration, it ispreferable to form all of the spool 28, the lower casing 26 and theupper casing 27 by the same or a similar resin composition.

FIG. 19 illustrates a process of packaging a photographic photosensitivestrip material by using a light-shielding thermoplastic resin film whichis the packaging material for a photographic photosensitive material ofthe invention. In the figure, 29 is the photographic photosensitivestrip material, 30 is a thermoplastic resin film guide member, 31 is alight-shielding thermoplastic resin film cover member, 32 is a joinedportion by heat sealing, adhesive, adhesive tape (single face or doubleface adhesive tape), etc., 33 is a core, and 34 is a bush for sealpackaging.

In the color masterbatch resin composition and the packaging materialfor a photographic photosensitive material of the invention,light-shielding material is dispersed uniformly by employing a specialresin composition, and thereby, adverse affects upon photographicphotosensitive materials are prevented, and favorable appearance can beensured. Moreover, fog with time, abnormal sensitivity, abrasion,pressure marks, etc. can be prevented.

EXAMPLES

Inventive Example 1

A light-shielding material mixture was prepared by mixing uniformly 2 kgof an interlaminar compound (mean particle size: 2.0 μm) of antimonypentafluoride and graphite and 1 kg of furnace carbon black (meanparticle size: 20 mμ, pH 8.0, oil absorption value: 110 ml/100 g,volatile components: 0.8%) using a ball mixer. To 3 kg of the mixture, 2kg of vinyl acetate resin and 0.7 kg of methyl acetate as a solvent werekneaded uniformly, and dried to obtain a color masterbatch resincomposition for a packaging material for a photographic material havinga light-shielding material concentration of 60 wt. %. The resincomposition was cut into cubic pellets having a length of 4 mm, a widthof 4 mm and a height of 3 mm (48 mm³).

10 wt. % of the color masterbatch resin composition pellets was mixeduniformly by a tumbler mixer with 90 wt. % of columnar pellets having adiameter of 3 mm and a height of 4 mm (28.3 mm³) of a thermoplasticresin for dilution of ethylene-octene-1 random copolymer resin having anoctene-1 content of 3 wt. % containing 0.05 wt. % of erucic amidelubricant, 0.10 wt. % of Irganox 1010, 0.2 wt. % of calcium stearate,0.10 wt. % of vitamin E and 0.1 wt. % of synthetic silica. The pelletmixture was conveyed to a hopper provided with a dryer (60° C.) by anautomatic loader.

60 wt. % of the light-shielding material concentration of the colormasterbatch resin composition is ten times as much as thelight-shielding material concentration of a packaging material to bemolded which is 6 wt. %, and the volume (48 mm³) of the colormasterbatch resin composition pellet is 1.7 times as large as the volume(28.3 mm³) of the pellet of the thermoplastic resin for dilution.

Using the above pellet mixture, a light-shielding L-LDPE resin inflationfilm 70 μm in thickness which is a packaging material for a photographicphotosensitive material was molded. The inflation film was excellent inphysical strength. The generation of microgrits was very few, and fisheyes and pinholes were quite none. Bleeding did not occur. Antistaticability was very excellent, and in the case of using it aslight-shielding bag static marks did not generate even under lowhumidity conditions of 30% RH or less. Moreover, various propertiesnecessary for packaging materials for a photographic photosensitivematerial, such as photographic properties, light-shielding ability,complete sealability by heat seal, etc. could be ensured for a longperiod.

Inventive Examples 2-8, Comparative Examples 1-5 and ConventionalExample 1

Resin compositions were prepared consisting of acrylic acid estercopolymer resin composed of 65 wt. % of methyl methacrylate and 30 wt. %n-butyl acrylate, rubber-containing polystyrene resin containing 6 wt. %of butadiene synthetic rubber, furnace carbon black having a meanparticle size of 21 mμ, a coloring power of 126%, an oil absorptionvalue of 76 ml/100 g, a pH of 8.0, polydimethylsiloxane having aviscosity of 20,000 centistokes, calcium stearate, synthetic silica anddi-t-butyl-P-cresol. The content of each component is shown in Table 1.Each resin composition was kneaded in a melted state and pelletized by adouble-screw extruder ("PCM-30", Ikegai Corp.) into columnar pelletshaving a diameter of 3 mm and a height of 4 mm. The pellets were driedat 70° C. with evacuating up to an oven-dry water content of not morethan 0.1 wt. % to obtain color masterbatch resin composition pellets fora packaging material for a photographic photosensitive material.

10 wt. % of the color masterbatch resin composition pellets were mixedwith 90 wt. % of columnar pellets having a diameter of 3.5 mm and aheight of 4 mm of a thermoplastic resin for dilution ofrubber-containing polystyrene resin containing 8 wt. % of butadienesynthetic rubber by a tumbler mixer for 30 minutes. Using an injectionmolding machine ("Netstal", Sumitomo Heavy Ind. Ltd.), the above pelletmixture was injection-molded at a mold clamping pressure of 150 ton intotest pieces for Izod impact strength testm, photographic film spools asshown in FIG. 13 which meet a photographic film cartridge having a shapeand a size of JIS K 7519-1982, cartridges for a photographic film asshown in FIG. 14 and film units with a lens as shown in FIG. 16. Theresults are shown in Table 1.

                                      TABLE 1                                     __________________________________________________________________________                                           Conven-                                                  Inventive            tional                                                                             Comparative    Test                                 2  3  4  5  6  7  8  1    1  2  3  4  5  Method             __________________________________________________________________________    Color Masterbatch                                                             Resin Composition                                                             Carbon Black  wt. %                                                                             20 20 20 20 20 20 20 20   20 20 20 20 20 --                 Acrylic Acid Ester                                                                          wt. %                                                                             15 35 45 50 55 25 55 0    0  10 50 65 30 --                 Copolymer Resin                                                               Rubber-Containing                                                                           wt. %                                                                             59 39 29 24 19 49 19 80   80 64 39 19 44.6                                                                             --                 Polystyrene Resin                                                             Polydimethylsiloxane                                                                        wt. %                                                                             5  5  5  5  5  5  5  0    0  5  0  5  5  --                 Ca Stearate   wt. %                                                                             0.5                                                                              0.5                                                                              0.5                                                                              0.5                                                                              0.5                                                                              0.5                                                                              0.5                                                                              0    0  0.5                                                                              0.5                                                                              0.5                                                                              0  --                 Synthetic Silica                                                                            wt. %                                                                             0.4                                                                              0.4                                                                              0.4                                                                              0.5                                                                              0.5                                                                              0.5                                                                              0.5                                                                              0    0  0.5                                                                              0.4                                                                              0.4                                                                              0.4                                                                              --                 di-t-Butyl-p-Cresol                                                                         wt. %                                                                             0.1                                                                              0.1                                                                              0.1                                                                              0.1                                                                              0.1                                                                              0.1                                                                              0.1                                                                              0    0  0.1                                                                              0.1                                                                              0.1                                                                              0  --                 Molded Article                                                                Color Masterbatch Resin                                                                     wt. %                                                                             10 10 10 10 10 10 13 10   10 10 10 10 10 --                 Composition                                                                   Rubber-Containing Polystyrene                                                               wt. %                                                                             90 90 90 90 90 90 88 90   90 90 90 90 90 --                 Resin for Dilution                                                            Carbon Black Content                                                                        wt. %                                                                             0.4                                                                              0.4                                                                              0.4                                                                              0.4                                                                              0.4                                                                              0.4                                                                              0.52                                                                             0.4  0.4                                                                              0.4                                                                              0.4                                                                              0.4                                                                              0.4                                                                              --                 Suitability for Spool                                                                       --  ∘                                                                    ⊚                                                                 ⊚                                                                 ∘                                                                                                                                       ⊚                                                                 ∘                                                                    ▴                                                                   ▴                                                                 ▴                                                                 ▴                                                                 ▴                                                                 ▴                                                                 A                  Photographic Properties                                                                     --  ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                    ▴                                                                   ▴                                                                 ∘                                                                    ∘                                                                    ∘                                                                    ▴                                                                 *B                 Last Torque   --  ⊚                                                                 ⊚                                                                 ⊚                                                                 ∘                                                                    ∘                                                                    ⊚                                                                 ∘                                                                    ▴                                                                   ▴                                                                 ⊚                                                                 ▴                                                                 ∘                                                                    ⊚                                                                 *C                 Izod Impact Strength                                                                        --  ⊚                                                                 ⊚                                                                 ∘                                                                    ∘                                                                                                                                       ⊚                                                                                                                                    ∘                                                                      ⊚                                                                 ⊚                                                                 ∘                                                                    ▴                                                                 ⊚                                                                 *D                 Fog           --  ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                                                                                       ∘                                                                    ∘                                                                                                                                                                                                            ∘                                                                    ▴                                                                                                                                    ∘                                                                    E                  Appearance    --                                                                     ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                    ∘                                                                    ▴                                                                   ▴                                                                 ▴                                                                 ∘                                                                    ∘                                                                    ▴                                                                 F                  Delamination  --  ∘                                                                    ∘                                                                    ∘                                                                                                                                                                                                          ∘                                                                    ∘                                                                    ∘                                                                      ∘                                                                    ∘                                                                    ∘                                                                    ▴                                                                 ∘                                                                    G                  Suitability for Cartridge                                                                   --                                                                     ⊚                                                                 ⊚                                                                                                                                                                                                       ⊚                                                                 ∘                                                                    ▴                                                                   ▴                                                                 ▴                                                                 ▴                                                                 ▴                                                                 ▴                                                                 H                  Suitability for Film Unit                                                                   --  ∘                                                                    ⊚                                                                 ⊚                                                                                                                                                                                                       ⊚                                                                 ∘                                                                    ▴                                                                   ▴                                                                 ▴                                                                 ▴                                                                 ▴                                                                 ▴                                                                 I                  __________________________________________________________________________     Evaluation was as follows:                                                    ⊚ . . . Very excellent                                         ∘ . . . Excellent                                                  . . . Practical                                                ▴ . . . Having a problem, improvement is necessary        

Testing methods are as follows:

A. Suitability for Spool

Evaluated by injection moldability of photographic film spools,injection molding for a long period, photographic properties, Izodimpact strength, fog, appearance, delamination, etc., collectively.

B. Photographic Properties

A 35 mm negative color photographic film with 24 exposures with an ISOphotographic speed 400 was wound around each photographic film spool,and loaded in a cartridge for photographic film having a shape and sizeof JIS K 7519-1982 with a slot for extending the photographic film towhich a light-shielding teremp cloth was attached. The completelight-shielding package thus formed was put in a container body for aphotographic film made of high density polyethylene resin, and sealed byattaching a corp made of low density polyethylene resin. The containerwas left in an air-conditioned room at 20° C. at 60% RH for one year,and then the photographic film was developed. Difference of photographicproperties (fog, sensitivity, tone, coloration) was measured from theoriginal photographic film before storing, and evaluated. Smallerdifference is better.

C. Last Torque

Load tension upon extending a photographic film. A motor was connectedto a pair of nip rolls which nip the leading end and extended aphotographic film through a torque pick-up, and a 35 mm negative colorfilm with 36 exposures was extended up to the last at a linear speed of40 mm/sec. The last torque was measured by the torque pick-up, and thetorque value was converted to a tension value. The measuring apparatusis disclosed in Japanese Patent KOKAI 62284355.

D. Izod Impact Strength

Measured according to ASTM D-256 (at 23° C.)

F. Fog

A negative color photographic film with an ISO photographic speed 400was wound around each photographic film spoo., and loaded in a cartridgefor photographic film in JIS 135 type, and exposed to light of 80,000luxes for 1 hour. Then, the photographic film was developed, fixed,washed with water, and dried, and evaluated by fogged degree of thephotographic film.

F. Appearance

Microgrits, uneven color and weldlines generated on eachinjection-molded photographic film spool were evaluated by visualinspection.

G. Delamination

Using the test piece for Izod impact strength test, the test piece wasfolded, and a cut line was formed by a knife. Then, peeled in the resinflow direction, and the peeled area was evaluated by visual observation.

H. Suitability for Cartridge

Evaluated by injection moldability of photographic film cartridges,injection molding for a long period, photographic properties, Izodimpact strength, fog, appearance, delamination, etc., collectively.

I. Suitability for Film Unit

As to each photographic film unit with a lens, evaluated similar to thetesting method H.

The articles of the invention were excellent in photographic properties(the dispersion of carbon black was excellent, the generation ofmicrogrits ware rare, halogen compounds and metal ions in the resin wereneutralized by calcium stearate, thermal decomposition of resin wasprevented by di-t-butyl-p-cresol). By blending synthetic rubber andpolydimethylsiloxane, last torque was decreased, and Izod impactstrength was improved. Moreover, since opacified greatly,light-shielding ability was improved, and fog did not occur, even whenlight-shielding material amount was decreased. Appearance was alsoexcellent. Since the masterbatch resin composition contained a suitableamount of acrylic acid ester copolymer resin, the uniformed dispersionof carbon black into a thermoplastic resin for dilution was improved,and microquits, uneven coloration and fog did not occur. Delaminationwas not generated, and accordingly, the articles of the invention wereexcellent as a packaging material for a photographic photosensitivematerial.

Inventive Example 9

Columnar pellets of a color masterbatch resin composition having adiameter of 3 mm and a height of 4 mm were prepared. The resincomposition was composed of 43 wt. % of low crystallinityethylene-butene-1 copolymer resin having a MFR of 5.0 g/10 minutes, adensity of 0.890 g/cm³ and a Vicat softening point of 98° C., 2 wt. % ofzinc stearate, 50 wt. % of conductive furnace carbon black having a meanparticle size of 16 mμ, an oil absorption value of 80 ml/100 g and a pHof 8.0, 0.3 wt. % of a hindered phenol antioxidant of tetrakismethylene-3-(3,5-di-t-butyl-4-bydroxyphenyl)propionate!methane(molecular weight: 118), 0. 2 wt. % of synthetic silica and 4.5 wt. % oflow molecular weight polyethylene resin having a number averagemolecular weight of 1700.

20 wt. % of the above color masterbatch resin composition pellets weremixed with 80 wt. % columnar pellets having a diameter of 35 mm and aheight of 4 mm of ethylene-butene-1copolymer resin having a MFR of 2.3g/10 minutes, a density of 0.919 g/cm³ and a Vicat softening point of129° C. containing 0.05 wt. % of erucic amide and 0.2 wt. % of calciumstearate, by a tumbler mixer for 30 minutes, and the pellet mixture wasmolded into a light-shielding film 70 μm in thickness which was apackaging material for a photographic photosensitive material under thefollowing inflation film molding conditions.

Inflation Film Molding conditions

Screw diameter: 50 mm .o slashed.

Screw L/D: 26/1

Compression ratio: 3.5

Ring die diameter: 100 mm .o slashed.

Ring dip lip clearance: 1.0 mm

Blow-up ratio: 1.2

Set temperature:

Cylinder: 180° C.

Resin temperature: 180° C.

Ring die: 180° C.

Cooling: Air cooling

Nip roll linear pressure: 5 kg/cm

The above packaging material for a photographic photosensitive materialof the light-shielding inflation film had complete light-shieldingability, and was excellent in heat sealing properties (heat sealstrength was great, heat seal strength descending with time was small,sealability with other materials was excellent). Moreover, physicalstrength was great, the generation of microgrits was very rare, andlubricity was excellent.

Furthermore, a volume specific resistance according to standards ofJapan Rubber Association (SRIS 2301) was small 6.2×105 Ω·cm. Aphotographic photosensitive material was taken in and out five timesfrom a light-shielding bag made of the light-shielding inflation film ina low humidity dark room at 20° C., 25% RH, and then, developed. As aresult, it was found that the occurrence of static marks was none,different from the case of using a conventioned bag, wherein staticmarks occurred. Photographic photosensitive materials (colorphotographic paper) were sealed in the bag, and left in anair-conditioned room at 20° C. at 60% RH for one year, and thendeveloped and fixed. As a result, fog did not occur at all. Photographicproperties (sensitivity, tone, color reproducibility, fog) were normalcompared with those before storing, and normal photographs were obtainedthrough normal developing conditions.

Inventive Example 10

10 wt. % of the pellets of the color masterbatch resin compositionprepared in Inventive Example 9 were mixed with 1.0 wt. % of calciumstearate, 5.0 wt. % of dimethylpolysiloxane having a viscosity of 10,000centistokes and 84 wt. % of columnar pellets having a diameter of 3.5 mmand a height of 4 mm of polystyrene resin having a MFR of 15 g/10minutes, a density of 1.04 g/cm³ and a Vicat softening point of 98° C.containing 6 wt. % of butadiene synthetic rubber by a tumbler mixer for60 minutes. The pellet mixture was kneaded in a melted state andpelletized by a double-screw extruder ("PCM-30", Ikegai Corp.) intocolumnar pellets having a diameter of 3 mm and a height of 4 mmcontaining 5 wt. % of carbon black. 10 wt. % of the above lowconcentration color masterbatch resin composition containing 5 wt. % ofcarbon black and 4.5 wt. % of dimethylpolysiloxane was mixed with 90 wt.% of the above polystyrene resin pellets containing 6 wt. % of butadienesynthetic rubber by a tumbler mixer for 30 minutes, and injection-moldedinto photographic film spools, photographic film cartridges andphotographic film units with a lens by using the same injection moldingmachine and the molds used in Inventive

Examples 2-8.

The molded articles were evaluated by the same testing methods employedin Inventive Examples 2-8. As a result, the photographic film spools hadvery excellent properties, i,e, the suitability for spool: ⊚, thephotographic properties: ◯, the last torque: ⊚, the Izod impactstrength: ⊚, the fog: ◯, the appearance: ◯, the delamination: ◯. Thephotographic film cartridges and the photographic film units with a lenshad also very excellent properties, and the suitability for cartride wasevaluated ⊚, and the suitability for film unit was also evaluated ⊚.

Inventive Example 11

100 parts by weight of ethylene-butene-l copolymer resin having a MFR of2.1 g/10 minutes, a density of 0.922 g/cm³, a melting point of 125° C.,a molecular weight distribution (Mw/Mu) of 3.5 and a butene-1content of4.2 mol. % was mixed with 10 parts by weight of maleicanhydride-modified ethylene-butene-1 copolymer resin having a MFR of 8g/10 minutes, a density of 0.920 g/cm³ a carboxyl group content of 5 g/1kg, 100 parts by weight of furnace type carbon black having a meanparticle size of 25 mμ and a pH of 8.0 of which the surface was coatedwith acrylic acid and 0.1 part by weight of an organic peroxide of2.5-dimethyl-2.5-di(t-butylperoxy)hexane by a ribbon blender. Themixture was kneaded in a melted state by a single-screw extruder (screwdiameter: 50 mm .o slashed., L/D=28) at 205° C., and extruded in astrand (diameter: 3 mm .o slashed.), into a water bath. After cooled,the strands were pelletized by cutting into 3 mm length pieces by acutter.

The pellets were dried up to an oven-dry water content of not more than0.1 wt. % at 80° C. under reduced pressure at 80 mm Hg for 2 hours toobtain columnar pellets having a diameter of 3 mm and a height of 3 mmof a color masterbatch resin composition for a packaging material for aphotographic photosensitive material. 10 wt. % of the above colormasterbatch resin composition pellets were mixed with 90 wt. % ofcolumnar pellets having a diameter of 3 mm and a height of 4 mm ofethylene-4-methylpentene-1 random copolymer resin having a MFR of 2.0g/10 minutes, a density of 0.920 g/cm³ and a 4-methylpentene-1 contentof 4 mol. % containing 0.05 wt. % of erucic amide, 0.1 wt. % ofantioxidant and 0.3 wt. % of calcium stearate as the thermoplastic resinpellets for dilution by an automatic weighing mixer in weight measuringtype ("Auto Color AC", Kawada Seisakusho) uniformly. The pellet mixturewas conveyed to a hopper of an extruder by an automatic loader, andmolded into a light-shielding L-LDPE resin inflation film 70 μm inthickness which was a packaging material for a photographicphotosensitive material under the following inflation film moldingconditions.

Inflation Film Molding conditions

Screw diameter: 50 mm .o slashed.

Screw L/D: 26/1

Compression ratio: 3.5

Ring die diameter: 100 mm .o slashed.

Ring dip lip clearance: 1.0 mm

Blow-up ratio: 1.2

Set temperature:

Cylinder: 180° C.

Resin temperature: 180° C.

Ring die: 180° C.

Cooling: Air cooling

Nip roll linear pressure: 5 kg/cm

The packaging material did not affect adversely photographic propertiesof photographic photosensitive materials, and had a great physicalstrength. The generation of microgrits was rare, and fish eyes andpinholes did not occur at all. Heat sealing properties were veryexcellent, and even when a light-shielding bag was prepared by a singlelayer film, complete light-shielding ability and moistureproofness couldalways be assured.

Inventive Example 12

1 wt. % of the color masterbatch resin composition pellets prepared inInventive Example 11 was mixed with 99 wt. % of columnar pellets havinga diameter of 3 mm and a height of 3 mm of homopolyethylene resin havinga MFR of 30 g/10 minutes, a density of 0.920 g/cm³ and a molecularweight distribution (Mw/Mn) of 4.5 containing 0.05 wt. % of oleic amide,0.1 wt. % of phenol antioxidant and 0.15 wt. % of dibenzylidene sorbitolcompound as the thermoplastic resin for dilution by an automaticweighing mixer ("Auto Color AC", Kawada Seisakusho) uniformly, and putin a hopper of an extruder.

The pellet mixture was kneaded in a melted state and injection-moldedinto caps shown in FIG. 10 by using a toggle type injection moldingmachine and a hot runner type mold with the number of cavities of 36 ata resin temperature of 190° C. at a mold clamping pressure of 200 ton ata molding cycle of 6 seconds,

The packaging material was excellent in the dispersion of carbon blackwhich was a light-shielding material, and uneven coloration did notoccur. Since the masterbatch resin composition was diluted at a highdilution ratio with a thermoplastic resin for dilution, the cost wassubstantially the same as the cost of the uncolored low densityhomoplyethylene resin which was very inexpensive. By using the resinhaving a small molecular weight distribution and a high MFR, moldshrinkage could be decreased to 1/3 or less of conventional colores capwithout degrading injection moldability, the blending effect of anucleating agent was enhanced, and crystallization rate was improved.Cooling time could be shortened sharply, and even rendering moldingcycle 6 seconds, molding troubles and troubles of fitting to a containerbody did not occur. Since coloring troubles caused by thermaldegradation of resin, clogging of an injection molding machine and shortshot trouble caused by the generation of microgrits did not occur atall, unmanned continuous molding was possible through day and nightwithout the occurrence of molding troubles, by using acomputer-controlled injection molding machine.

Inventive Example 13

2 wt. % of the color masterbatch resin composition pellets prepared inInventive Example 11 was mixed with 98 wt. % of columnar pellets havinga diameter of 3 mm and a height of 4 mm of homopolyethylene resin havinga MFR of 30 g/10 minutes, a density of 0.975 g/cm³ and a molecularweight distribution (MW/MN) of 7.6 containing 0.05 wt. % of oleic amide,0.2 wt. % of oleic monoglyceride, 0.05 wt. % of a phenol antioxidant,0.05 wt. % of a phosphite antioxidant, 0.2 wt. % of calcium stearate,0.2 wt. % of an organic nucleating agent and 0.3 wt. of a hydrotalcitecompound as the thermoplastic resin for dilution by an automaticweighing mixer in weight measuring type ("Auto Color AC", KawadaSeisakusho) uniformly.

The pellet mixture was kneaded in a melted state and injection-moldedinto container bodies shown in FIG. 11 by using a toggle type injectionmolding machine (L/D=25) and a hot runner type mold with the number ofcavities of 36 at a melted resin temperature of 210° C. at a moldlamping pressure of 200 ton at a molding cycle of 6 seconds.

The packaging material was excellent in the dispersion of carbon blackwhich was a light-shielding material, and uneven coloration did notoccur. Since the masterbatch resin composition was diluted at a highdilution ratio with a thermoplastic resin for dilution, the cost wassubstantially the same as the cost of the uncolored high densityhomopolyethylene resin which was very inexpensive. By using the resinhaving a small molecular weight distribution and a high MFR, moldshrinkage could be decreased to 1/2 or less of conventional colorescontainer body without degrading injection moldability, the blendingeffect of a nucleating agent was enhanced, and crystallization rate wasimproved. As a result, cooling time could be shortened sharply, and evenrendering molding cycle 6 seconds, molding troubles buckling andtroubles of fitting to a container cap did not occur. Since coloringtroubles caused by thermal degradation of resin, clogging of aninjection molding machine and short shot trouble caused by thegeneration of microgrits did not occur at all, unmanned continuousmolding for a long period was possible through day and night without theoccurrence of molding troubles, by using a computer-controlled closedsystem injection molding machine.

Inventive Example 14

2 wt. % of the color masterbatch resin composition pellets prepared inInventive Example 11 was mixed with 48 wt. % of columnar pellets havinga diameter of 4 mm: and a height of 3 mm of polystyrene resin having aMFR of 15 g/10 minutes, a density of 1.04 g/cm³, a molecular weightdistribution (MW/MN) of 3.0 and a butadiene rubber content of 4 wt. %containing 0.3 wt. % of calcium stearate, 0.3 wt. % of methylenebisoleicamide, 0.1 wt. % of a phenol antioxidant and 1.0 wt. % of a hydrotalcitecompound and 50 wt. % of columnar spool recycled pellet having adiameter of 4 mm and a height of 3 mm as the thermoplastic resin fordilution by an automatic weighing mixer in weight measuring type ("AutoColor AC", Kawada Seisakusho) uniformly.

The pellet mixture was kneaded in a melted state and injection moldedinto spools shown in FIG. 13 by using a toggle type injection moldingmachine (L/D=25) and a semi-hot runner type mold with the number ofcavities of 36 at a melted resin temperature of 190° C. at a moldclomping pressure of 200 ton at a molding cycle of 6 seconds.

The packaging material was excellent in the dispersion of carbon blackwhich was a light-shielding material and uneven coloration did notoccur, and complete light-shielding ability could be ensured. Since themasterbatch resin composition was diluted at a high dilution ratio withan uncolored butadiene rubber-containing polystyrene resin and recycledpolystyrene resin for dilution, the cost was very inexpensive. Since thespool was excellent in lubricity, rare generation of microgrits, andbeautiful appearance, winding torque and unwinding torque of aphotographic film was small, winding stop at midway did not occur atall. Since coloring trouble caused by thermal degradation of resin,clogging of an injection molding machine and short shot trouble causedby the generation of microgrits did not occur at all, unmannedcontinuous molding for a long period was possible through day and nightwithout the occurrence of molding troubles, by using acomputer-controlled closed system injection molding machine. As aresult, to remove inspection except automatic inspection of processingwas possible.

As above, it was found that the color masterbatch resin composition ofInventive Example 11 could be dispersed into most thermoplastic resins,such as polyolefin resins, polystyrene resins, polyamide resins andpolyester resins, used as a resin for dilution, and had excellentproperties capable of ensuring photographic properties and completelight-shielding ability necessary for packaging materials for aphotographic photosensitive material.

We claim:
 1. A packaging material for a photographic photosensitive material, comprising a color masterbatch resin composition for a packaging material, which comprises a thermoplastic resin and a light-shielding material having a surface which has been coated with a surface-coating material dispersed into the thermoplastic resin, a resin composition for dilution, and a lubricant,wherein the thermoplastic resin is a rubber-containing aromatic monovinyl resin which has a melt flow rate of 3 to 40 g/10 minutes, a Rockwell hardness of M 40 or more, a Vicat softening point of 78° C. or more, a bending elastic modulus of 20,000 kg/cm² or more and which contains 1 to 12 wt. % of a rubber material having a mean particle size of 0.1 to 10 μm; wherein the surface-coating material is present in a coating amount of 0.001 to 2 wt. % of the weight of the packaging material for a photographic photosensitive material and is an ester of (i) an aliphatic monocarboxylic acid having 20 to 40 carbon atoms and (ii) a monovalent aliphatic alcohol having 20 to 40 carbon atoms; wherein the light-shielding material is carbon black which has a DBP oil absorption value of not less than 50 ml/100 g and a total sulfur components content of 0.9% or less; and wherein the lubricant is present in an amount of 0.01 to 10 wt. % of the weight of the packaging material for a photographic photosensitive material and is a fatty acid metal salt having 10 to 35 carbon atoms and a melting point of 70° to 180° C.
 2. The packaging material for a photographic photosensitive material claim 1 wherein the color masterbatch resin composition for a packaging material comprises 100 parts by weight of a polystyrene resin and/or an ABS resin, 0.2 to 50 parts by weight of the carbon black having a total sulfur components content of 0.9% or less and having an iodine adsorption amount of 20 mg/g or more, and a thermoplastic resin for dilution;wherein the polystyrene resin and/or ABS resin has a melt flow rate of 3 to 40 g/10 minutes, a Rockwell hardness of M 40 or more, a Vicat softening point of 78° C. or more, and a bending elastic modulus of 20,000 kg/cm² or more; wherein the carbon black has a DBP oil absorption value of not less than 50 ml/100 g and a mean particle size of 10 to 120 mμ; and wherein the lubricant is present in an amount of 0.01 to 10 wt. % of the weight of the packaging material for a photographic photosensitive material and is a fatty acid metal salt having 10 to 35 carbon atoms and a melting point of 70° to 180° C.
 3. The packaging material for a photographic photosensitive material of claim 2 which is made by a process comprising the steps of mixing a color masterbatch resin composition and a thermoplastic resin for dilution in an amount twice as much as or more by weight of the color masterbatch resin composition, molding by keeping a hopper and a resin feed opening of an extruder under reduced pressure conditions lower than an atmospheric pressure.
 4. The packaging material for a photographic photosensitive material of claim 2 which packaging material comprises 100 parts by weight of the color masterbatch resin composition for a packaging material and 300 parts by weight or more of the thermoplastic resin for dilution mixed almost uniformly, said packaging material being prepared by supplying the mixed resin in a melted state to a mold through a line mixer without any movable part between an extruder and the mold.
 5. The packaging material for a photographic photosensitive material of claim 2 which has been molded from a mixture of pellets of the color masterbatch resin composition for a packaging material for a photographic photosensitive material with pellets of the thermoplastic resin for dilution in a predetermined ratio by an automatic weighing mixer, wherein evaporable substances have been removed from the resin mixture through their evaporation by keeping a hopper and a resin feed opening of an extruder to which the mixed pellets are supplied under reduced pressure conditions lower than an atmospheric pressure.
 6. The packaging material for a photographic photosensitive material of claim 2 wherein the thermoplastic resin for dilution is a rubber-containing polystyrene resin for dilution, and wherein the packaging material has been molded from a mixture of pellets of the color masterbatch resin composition for the packaging material for the photographic photosensitive material with pellets of the rubber-containing polystyrene resin for dilution in a predetermined ratio almost uniformly, by injecting the resin mixture into a mold of which a wall temperature of core and cavity portions is from 110° to 250° C., and taking the molded packaging material out of the mold when the wall temperature of core and cavity portions is less than a glass transition temperature of the rubber-containing polystyrene. 